This chapter has three Parts. Part 1 attempts to analyze the concept “information” (in some selected contexts where it has been used) in order to understand the consequences of representing and processing information, quantum mechanically. There are at least three views on ‘Information’ viz., ‘Semantic Naturalism’, ‘the Quantum Bayesian Approach’ and ‘Information is Physical’ approach. They are then critically examined and at last one is given preference. Part 2 of the chapter then goes on to discuss the manner in which the study and quantification of “Qubit” (Quantum bit), Superposition and Entanglement, comprise the three pillars of Quantum Information Science and enable the discipline to develop the theory behind applications of quantum physics to the transmission and processing of information. In Part 3 we take up the issue that although it might appear bewildering, the physical approach to Quantum Information Science is equally proficient in dealing with its impact on the questions of “consciousness,” “freewill” and biological questions in the area known as “bioinformatics.”
- Meaning and Types of Information
- The role of ‘Qubit’
- ‘Superposition’ and ‘entanglement’ in Quantum Information Science and their applications
- Orch OR Model
- biological theories of mind
Quantum Information Science addresses the question as to how the fundamental laws of quantum physics can be exploited in order to explain in what way information is acquired, transmitted and processed, by drawing insights from various subfields of physical sciences, computer science, mathematics, and engineering. Quantum Information Science also combines fundamental research with practical applications.
The history of quantum information began at the turn of the 20th century when classical physics was revolutionized into quantum physics. The field of quantum information bloomed two decades ago when scientists realized that quantum physics could be used to transmit and process information in more efficient and secure ways. The development of quantum algorithm and communication protocols as well as the possibilities of implementing them with different systems, has established the field of quantum information science as one of the most promising fields for the 21st century.
The emergence of Information theory as studies of the transmission, processing, extraction, and utilization of information received immediate worldwide attention in the late forties. It was made possible by the publication of Claude E. Shannon’s classic paper “A Mathematical Theory of Communication.” .
Shannon for the first time introduced the qualitative and quantitative models of communication as statistical processes underlying information theory. Thus, Information theory often concerns itself with measures of information distributions and their application.
There is an urgent need to examine the foundational principles of quantum information and quantum physics in order to understand how we can dramatically improve their applications. The relevant utility of quantum computers has led to the possibility of simulating the complex quantum systems that appear in fields, such as condensed matter physics, high energy physics or chemistry. To do this, it is often necessary to build a scalable quantum computer (often called quantum simulators) and not necessarily an analog one. Quantum information science also has strong connections with quantum sensing and metrology, quantum simulation, quantum networks, and quantum dynamics. Issues in Quantum Information Science also found applications in areas, including statistical inference, cryptography, neurobiology, perception, linguistics, bioinformatics, quantum computing, information retrieval, plagiarism detection, pattern recognition, anomaly detection, biology and many other areas.
2. “Information” in quantum information science: What does the word mean?
Understanding the concept “information” is of importance to all the information disciplines. Perhaps for that reason, it is a term that has been defined in countless ways, over many areas in Quantum Information Science. It would be fair to say that there is no widely agreed-upon definition or theoretical conception of the term.
According to Luciano Floridi  the word “information” commonly refers to at least four kinds of mutually compatible phenomena:
Information in something (e.g. a pattern or a constraint).
Information about something (e.g. a train timetable)
Information as something (e.g. DNA, or fingerprints)
Information for something (e.g. algorithms or instructions)
These four phenomena commonly referred to by the word “information” are used so metaphorically or in such an abstract way that the meaning of the word “information” looks quite unclear. In spite of this lack of clarity in the meaning of information, Floridi was primarily concerned with efforts in rethinking and “reengineering” our societal concerns for “information” in the digital age.
Floridi’s main interest in Quantum Information Science relates to the problems raised by analysis of “information” in two different areas:
Information Theory that takes into account (i) technical problems concerning the quantification of information first dealt with by Shannon’s theory and (ii) the problems concerning the impact and effectiveness of information on human behavior and
semantic problems (semantics is concerned with how we derive meaning) relating to meaning of life, truth and being Human in a “Digital reality” or “Hyperconnected Era” as the development and widespread use of information communication technologies (ICTs) are having a radical impact on the human condition.
In view of the lack of agreement about the definition of the term “information,” as shown above, the main objective in Part 1, will be to lay out some of the major theoretical constructions giving rise to the classes of definitions of the term “information” that are currently or recently in use. What binds these theoretical constructions together is the claim that the technical notion of “information” can be specified only by using a purely mathematical and physical vocabulary. In what follows, we will discuss a few theoretical constructions.
2.1 The semantic naturalism
“Semantics” involves the
There is in philosophy a tradition occupied by those who hope or expect to achieve the reduction of semantics and related concepts to respectable
John Searle [4, 5] argues that mere calculation does not, of itself, evoke conscious mental attributes, such as understanding or intentionality, e.g. the results of mathematical insight, do not seem to be obtained algorithmically. In his famous “Chinese room argument,” Searle claims to demonstrate that computers mimic someone who understands Chinese even though it does not know a word. Computers process symbols in ways that simulate human thinking, but they are actually mindless, as they do not have any subjective, conscious experience.
Fred Dretske in his
This is also Dretske’s first major defense of an
The main thrust of Dretske approach, by taking advantage of the new physics, is to show how the idea of a non-algorithmic conscious brain, is capable of filling the so-called ‘gap’ between
The earliest systematic attempts to understand
Dretske articulates his
Thus, a signal correlated with p will fail to carry the information that p if the correlation is merely accidental or statistical: my thermometer carries information about the temperature of my room and not somebody else’s room, even if the two rooms have the same temperature. It is because the state of my thermometer supports counterfactuals about the temperature of my room but not about the temperature of somebody else’s room. Hence, it is a true generalization that if the temperature of my room were different, the state of my thermometer would be different. In contrast, it is not generally true that if the temperature of somebody else’s room were different, the state of my thermometer would be different.
According to Dretske the engineering aspects of mechanical communication systems are relevant and he goes on to demonstrate precisely what their relevance is. Dretske’s proposal is linking the information theory to the amount of information that an individual event carries about another event or state of affairs. He argues that if a signal is to carry the information that q it must, among other things, carry
There might be problems in specifying absolute amounts of information; but it is comparative amounts of information with which Dretske is concerned, in particular, with whether a signal carries as much information as is generated by the occurrence of a specified event, whatever the absolute values might be.
In our system of communication and information thus far, there is an apparent failure to provide a
Secondly, we learn from the circumstances certain beliefs in which the information these beliefs carry is not the belief’s content. Take for example a child who learns to token a belief with a content about tigers by seeing pictures of tigers. In such cases her belief states carry information about pictures, in spite of the fact that their content is about tigers. Dretske’s account will end up assigning the wrong truth conditional contents to these beliefs.
Thirdly, according to Dretske a teleological characterization of the state tokens, although the relevant information fixes the content of the beliefs. However, Dretske’s main idea is that the informational content fixes the belief’s semantic content in these instances of the belief state and they are reinforced by the relevant behavior which produces them. Although this is a naturalistic characterization of this class of beliefs, it is debatable whether it assigns appropriate contents. One may easily come up with situations in which a false token of a belief produces behavior.
Finally, it is believed that informational theories are the most promising proposals for reconciling naturalism with intentional realism. However, it remains to be shown that there is an informational theory of content that satisfies the constraint, viz. `ps cause Ss’ is a law (where S has property p as its content). Of course, this does not mean that no informational theory can succeed. However, it does mean that, so far, appeals to information have not resolved the problem of naturalizing content.
3. The quantum theory as usually presented in terms of Bayesian approach
Taking Strawson’s stricture of construing ‘information’ as a singular substantive, disembodied abstract entity as “an ancient, but no longer a respectable error,” we need to look at
The fallacy of construing information as a disembodied abstract entity can be avoided by taking
It was in the second half of the 18th century, there was no branch of mathematical sciences called “Probability Theory”. It was known simply by a rather odd-sounding “
In this essay, Bayes described a simple theorem concerning joint probability which gives rise to the calculation of inverse probability. This is called Bayes’ Theorem. It shows that there is a link between
What is conveyed by this formula is that we update our belief, (i.e.
3.1 Objective certainty in finite probability spaces
In 1935, Einstein, Podolsky, and Rosen made the following sufficient condition for reality. Einstein, Podolsky and Rosen maintain that
Rudolf Carnap and Yehoshua Bar-Hillel, also in Carnap Rudolf and Bar-Hillel Yehoshua 
3.2 The essential claim of quantum Bayesian approach
Quantum theory (as usually presented with the Born Rule, in its simplest form), states that the probability density of finding a particle at a given point, when measured, is proportional to the square of the magnitude of the particle’s wave function at that point. It provides an algorithm for generating probabilities for alternative outcomes of a measurement of one or more observables on a quantum system. Traditionally they are regarded as objective. On the other hand, a subjective Bayesian or personalist view of quantum probabilities regard quantum state assignments as subjective.
3.3 Critical remarks
At the turn of the 21st century Quantum Bayesianism emerged as a result of the collaborative work among Caves et al. .
First, the word “Bayesian” does not carry a commitment to denying objective probability and a “Quantum Bayesian” insists that probability has no physical existence even in a quantum world. The probability ascriptions arise from a particular state that are understood in a purely Bayesian manner. Caves, Fuchs, and Schack refute Einstein, Podolsky, and Rosen’s argument that quantum description is incomplete by giving up all objective physical probabilities. They would rather identify probability 1 with an
Secondly, the quantum state ascribed to an individual system is understood to represent a compact summary of
4. ‘Information is Physical’ Approach: An alternative
The fact that ‘information is physical’ means and that the laws of Quantum Mechanics can be used to process and transmit it in ways that are not possible with classical systems,
4.1 Foundational issues
Quantum Physics, ever since it was advanced in the 1920s, has led to countless discussions about its meaning and about how to interpret the theory correctly. These discussions relate to the issues like the Einstein-Podolsky-Rosen paradox, quantum non-locality and the role of measurement in quantum physics and several others. For example, in stating their paradox on the basis of a certain restricted set of correlations for a pair of systems in a particular entangled state (explained below), Einstein et al. , claimed that the phenomenon of entanglement conflicts with certain basic realist principles of separability and locality that all physical theories should respect. Otherwise we have to regard quantum states as ‘incomplete’ descriptions of reality.
Challenging Einstein in 1927 during the
Earlier around 1926, Erwin Schrödinger had already developed a mathematical formula to describe such “matter waves”, which he pictured as some kind of rippling sea of smeared-out particles. But Max Born showed that Schrödinger’s waves are, in effect, “waves of probability”. They encode the statistical likelihood that a particle will show up at a given place and time based on the behavior of many such particles in repeated experiments. When the particle is observed, something strange appears to happen: the wave-function “collapses” to a single point, allowing us to see the particle at a particular position.
In recent years research into the very foundations of quantum mechanics has given rise to the present field, i.e. Quantum Information Science and Technology. Thus the use of quantum physics could revolutionize the way we process and communicate information. The slogan that ‘Information is Physical’ is often presented as the fundamental insight at the heart of quantum information theory; after all ‘information’ is an abstract noun referring to something physical, transmitted from one point to another and it is frequently claimed to be entailed, or at least suggested, by the theoretical and practical advances of quantum information and computation.
4.2 Claude Shannon
The concept of information and technical notions of information, is derive from the work of Claude Shannon in his
We must take note first that the notion of “information” in the semantic aspects of communication did not concern Shannon. His notion of “information” is often called
Secondly, Shannon, in his mathematical theory of information, introduces the term “
Shannon borrowed the term “entropy” from John von Neumann. However, in Shannon’s undertaking, the notion of
Finally, the important aspect of communication can be specified by bits, which signify the physical aspect of the message and yet, somehow, it carries the meaning of the message from one point to another by encoding and decoding. However, in Shannon’s mathematical theory of information, the messages in question will not have meaning. For example, while we talk in a telephone what is transmitted is not what is said into the telephone, but an analogue signal. This analogue signal records the sound waves made by the speaker, which is transmitted digitally following an encoding. Thus, a communication system consists of an information source, a transmitter or encoder, (possibly noisy) a channel, and a receiver or decoder. These are the physical aspect of the message and what mainly concerns information scientists and engineers.
John Barwise and Jerry Seligman , identify the ‘inverse relationship principle’. The inverse relationship principle says that the informativeness of a piece of information increases as its probability decreases. This position is closely linked to the notion of
4.3 Rolf Landauer
Perhaps the most vociferous proponent of the idea that ‘information is physical’ was the late Rolf Landauer. In the two articles by him and one related to his work, viz., Landauer Rolf [14, 15, 16, 17], Landauer made a very important and new observation, i.e. that information is not independent of the physical laws used to store and processes it. Information is physical, or is a fundamental constituent of the universe. Landauer’s point is that whenever we find information, we find it inscribed or encoded somehow in a physical medium of whatever kind.
Although modern computers rely on quantum mechanics to operate, the information itself is still encoded classically.
Moreover, it seems that Quantum Information Theory itself provides an apt illustration of the claim that ‘Information is Physical’. But why is it that this claim is being made?
Since Landauer’s very first work, viz., Landauer Rolf , “Dissipation and heat generation in the computing process,” it was argued that information has a physical nature. As Galindo and Martin-Delgado in , point out that information is normally printed on a physical support, it cannot be transported faster than in vacuum, and it abides by natural laws. Moreover, they maintain that the statement that information is physical does not simply mean that a computer is a physical object, but in addition that information itself is a physical entity. In turn, this implies that the laws of information are restricted or governed by the laws of physics, in particular, those of quantum physics. Thus, information is not a disembodied abstract entity; it is always tied to a physical representation.
The first important results supporting the idea that “information is physical” was Landauer’s
It must be emphasized that Landauer’s principle is valid both in classical and quantum physics.
Let us take a look at two ways the experts reacted to this view:
The question is: do the truly fundamental laws of nature concern, not waves and particles, but “information”?
According to one view the truly fundamental laws of Nature concern information, not waves or particles and it is taken to be the basic postulate. For example, it is known that quantum key distribution is possible but ‘quantum bit’ commitment is not and that nature is nonlocal (but not as nonlocal as is imposed by causality).
According to the other view: “Information is information, not matter or energy” (, p. 132).
This view will be supported by Shannon. For Shannon what a sender transmits to a receiver is not information but a message. While defining information Shannon is strictly concerned with the potential selections of messages or, more precisely, of the signs available in order to codify them, Shannon’ theory does not come to grips with communication as transmission of meaning or with information as the meaning of a message. His theory is mainly concerned with codification and transmission of messages. It equates two terms that are apparently opposed, namely information and uncertainty. What Shannon aims to quantify is not an ‘information flow,’ , but the transmission of messages that can be continuous, discrete or mixed. This transmission is based on a medium or, more precisely, on a messenger and is understood as a formal relation between messages.
5. The view that ‘Information is Physical’ is the Foundation of Quantum Information Theory
Claude Shannon in a truly remarkable paper, Claude E. Shannon , laid down the foundations of the subject. In this paper Shannon claims that the main concern of Quantum Information Theory is as follows:
The Quantum Information Theory is much richer and more complex (than its classical counterpart) and it is inherently interdisciplinary in nature, since it touches on multiple fields and brings physicists, computer scientists, and mathematicians together on common goals.
It is far from being complete but has already found application areas well beyond the processing and transmission of information. In particular, it provides a new perspective to investigate, characterize, and classify the complex behavior of large quantum systems, ranging from materials to chemical compounds, high energy problems, and even holographic principles.
Nevertheless, even if Quantum Information Theory reinforces the notion that ‘Information is Physical,’ based on quantum physics, the notion itself is also relevant within classical physics.
5.1 Shannon’s definition of quantity of information
Shannon defined the ‘quantity of information’ produced by a source, for example, the quantity in a message by a formula similar to the equation that defines thermodynamic entropy in physics. In classical thermodynamics, entropy is a property of a thermodynamic system that expresses the direction or outcome of spontaneous changes in the system. According to Shannon Entropy predicts that certain processes are irreversible or impossible, despite not violating the conservation of energy.
Shannon introduced as his most basic term, viz.
Shannon’s paper contained two theorems. The first of these is the
The second theorem,
Thus, a new approach emerges as a result of treating information as a quantum concept and to ask what new insights can be gained by encoding this information in individual quantum systems.
5.2 Generalizations and Laws in quantum information science
While we often treat
However, what does it mean to say that information obeys the laws of physics. In Quantum Information Theory this amounts to claiming that both the transmission and processing of information are governed by
The term for a
On the other hand, in quantum information science, the basic variable is the
Electrons possess a quantum feature called
One of the innovative and unusual features of Quantum Information Science is the idea of “superposition” (explained below) of different states. A quantum system can be in a “superposition” of different states at the same time. Consequently, a quantum bit can be in both the |0〉 state and the |1〉 state simultaneously. This new feature has no parallel in classical information theory. Schumacher in , coined the word “qubit” to describe a quantum bit.
The job of the weird symbols “|” and “⟩” (the so-called the “bra-ket” notation, was introduced by Paul Dirac in . It is essentially to remind us that
Thus one of the novel features of Quantum Information Science is that a quantum system can be in a “superposition” of different states. In a sense, the quantum bit (or “qubit”) can be in both the |0〉 state and the |1〉 state
It is also claimed that in Quantum Computing a “qubit” carries information. The question is where is the extra information kept. The usual answer is that the extra information lies embedded in a
Suppose that the two vectors |0〉 and |1〉 are
Consider a situation where the two vectors |0〉 and |1〉 are linearly independent. This means that we cannot describe |0〉 in terms of |1〉 and vice versa. Nevertheless, it is feasible to describe all possible vectors in 2D space using both the vectors |0〉 and |1〉 and our rules of addition and multiplication by scalars,
It is maintained that the vectors |0〉 and |1〉 form a “basis” because of the fact that (i) the vectors |0〉 and |1〉 are linearly independent, and (ii) can be used to describe any vector in 2D space (Figure 2) using vector addition and scalar multiplication. When the vectors are both orthogonal and normalized, they construe an “orthonormal” basis.
5.2.2 function, Schrödinger equation and the dynamics of quantum mechanics
In Quantum Mechanics, the
The Schrödinger equation is supposed to answer the question as to how the states of a system change with time. It is in the form of a differential equation and it captures the ‘dynamics’ of quantum mechanics: it describes how the wave function of a physical system evolves over time.
Schrödinger’s equation gives an answer to the question: what happens to the de Broglie wave associated with an electron if a force (gravitational or electromagnetic) acts on it. The equation gives the possible waves associated with the particle a number associated with any position in space at an arbitrary time (i.e. functions of position and time). The general form of this wave function is:
The essence of the Schrödinger’s equation is that, given a particle and given the force system that acts (say, gravitational or electromagnetic), it yields the wave function solutions for all possible energies. Thus a particle can be described by a state vector or wave function whose evolution is provided by the Schrödinger equation. Hence, the Schrödinger equation, being a time-evolution equation, will make vary with time.
Qubit”and Schrödinger equation
5.2.4 What is quantum computing?
Basically, Quantum computing is concerned with processing information by harnessing and exploiting the amazing laws of quantum mechanics. The use of long strings of “bits” in traditional computers encode either a zero or a one. In contrast with that a quantum computer uses quantum bits, or qubits. The difference can be explained as follows: a qubit is a quantum system that encodes the zero and the one into two distinguishable quantum states. However, because qubits behave quantumly, we can capitalize on the phenomena of “superposition” and “entanglement,” which is not possible in the case of using “bits,” as an encoding device.
5.3 Superposition and entanglement
These two concepts might baffle us, since we do not come across the phenomena they describe in our everyday lives. Only in the event of our looking at the tiniest quantum particles, atoms, electrons, photons and the like, that we see these intriguing things, like
Superposition essentially subscribes to the principle that a quantum system can be in multiple states
18.104.22.168 Schrödinger’s cat
In 1935, Erwin Schrödinger conjured up a famous
It is certainly counterintuitive to think of the possibility of an organism to be in such a superposition of both alive and dead states (Figure 3). It also dramatically reveals the baffling consequences of quantum mechanics.
22.214.171.124 The double-slit experiment
Another well-known example of quantum superposition is the double-slit experiment in which a beam of particles passes through a double slit and forms a wave-like interference pattern on a screen on the far side.
Based on this experiment quantum interference is explained by saying that the particle is in a superposition of the two experimental paths: one passage is through the upper slit and the second passage is through the lower slit. Correspondingly a quantum bit can be in a superposition of |0〉 and |1〉. The implication seems to be that each particle passes simultaneously through both slits and interferes with itself. This combination of “both paths at once” is known as a superposition state .
It must be noted here that the particles. After going through the two slits, will turn into two sets of waves, Figure 4, in accordance with quantum mechanical principles. Moreover, at some points the two sets of waves will meet crest to crest, at other points the crest will meet the trough of the other wave. Accordingly two possibilities will arise: (i) in Figure 5, where crest meets crest, there will be
A particle tends to appear more often at some places (regions of constructive interference) and do not appear very often at other places (regions of destructive interference). However, the likelihood of finding the particle at a particular point can be described only probabilistically.
126.96.36.199 Superposition and quantum information science
In the two experiments explained above we have seen one of the features of a quantum system (viz, Superposition) whereby several separate quantum states can exist at the same time by superposition.
The Quantum Information Science claims that each electron will exist spin up and spin down, until it is measured. Till measurement is done it will have no chance of being in either state. Only when measured, it is
5.3.2 The problem of measurement
Delving into the issue of
5.3.3 Inherent uncertainty
In 1927 Heisenberg shook the physics community with his
The formula states that the more precisely the position of some particle is determined, the less precisely its momentum can be known, and vice versa.
The uncertainty principle, the wave-particle duality, the wave collapsing into a particle when we measure it together lead to the claim that the probability of the same particle being there in several places at the same time cannot be ruled out, i.e. ‘smeared out’ multiple positions at a time.
The smiley face shows, Figure 7, the location of the particle in one peak, but then there are many such places as the multiplicity of smiley faces show.
5.3.4 Superposition and the power of a quantum computer
We have already seen (in Section 5.2.1) that whereas classical computing uses “bits” for data processing, quantum computing uses qubits. We have also scrutinized that the practical difference between a bit and a qubit is: a bit can only exist in one of two states at a time, usually represented by a 1 and a 0, whereas a qubit can exist in both states at one time.
Moreover we have observed that the phenomenon of “superposition” allows the power of a quantum computer to grow exponentially with the addition of each bit. For example, two bits in a classical computer provides four possible combinations—00, 01, 11, and 10, but only one combination at a time. Two bits in a quantum computer provides for the same four possibilities, but, because of superposition, the qubits can represent all four states at the same time, making the quantum computer four times as powerful as the classical computer. So, adding a bit to a classical computer increases its power linearly, but adding a qubit to a quantum computer increases its power exponentially: doubling power with the addition of each qubit.
5.3.5 Application of superposition in solving engineering problems
The principle of superposition is useful for solving simple practical problems, but its main use is in the
For example, in quantum science, the
Entanglement in quantum mechanics is considered to be an extremely strong correlation and inextricable linkage that may found between different particles of the same kind and with the same physical property. It has been observed that such linkage and intrinsic connection, subsisting between Quantum particles, is so robust, that two or more quantum particles separated albeit by great distances, may be placed at opposite ends of the universe, can still interact with each other in perfect unison. This seemingly impossible connection led Einstein to describe entanglement as “spooky action at a distance.”
This intriguing phenomenon demonstrates that it is possible for scientists and researchers to generate pairs of qubits that are “entangled,” which amounts also to saying that two members of a pair exist in a single quantum state. Thus, they claim that if we change the state of one of the qubits, it will bring about instantaneous change in the state of the other one in a predictable way, even if they are separated by very long distances.
The notion of entanglement was coined by Erwin Schrodinger in order to signify the peculiar properties of quantum correlations. In the
For example, consider a pair of qubits. Suppose that each one is described by a state vector: the first one by ∣a⟩ and the second one by ∣b⟩. One might therefore think that the most general state of the two qubits should be represented by a pair of state vectors, ∣a⟩∣b⟩, with one for each qubit. Indeed, such a state is certainly possible, but there are other states that
Example of entanglement when a measurement is made: a subatomic particle decays into an entangled pair of other particles. Essentially, quantum entanglement suggests that acting on a particle here, can instantly influence a particle far away. This is often described as
5.4.1 Entanglement and quantum information science
Quantum entangled states play a crucial role and have become the key ingredient in the field of Quantum Information Science.
It will be a fair question to ask as to why does the effect of
Schrödinger, (unlike Einstein, the most skeptical about
5.4.2 Application of entanglement
The interpretation of quantum states, in particular the interpretation of so-called ‘entangled states’ exhibit peculiar
Quantum entanglement, more often is viewed as a physical resource, which enables us to communicate with perfect security, build very precise atomic clocks, and even teleport small quantum objects, dense coding and cryptography.
5.4.3 In what way entanglement enables us to communicate with perfect security
Quantum entanglement offers a new modality for communications that is different from classical communications. It has been claimed that entanglement enhances security in secret sharing.
Quantum cryptography (it is a method of storing and transmitting data quantum mechanically in a particular form so that only those for whom it is intended can read and process it) to a great extent revolves around quantum computing. The entanglement concept is one tool used in quantum computing, e.g., in the use of transmitting data via entangled Qubit, which is a unit of quantum information that is stored in a quantum system. Quantum cryptography utilizes photons and depends on the laws of physics rather than very large numbers and the deciphering of cryptographic codes.
It appears that we are perched on the edge of a quantum communication revolution that will change transmission of information, information security and how we understand privacy.
Two central concepts of quantum mechanics are Heisenberg’s uncertainty principle and nonlocality. Nonlocality plays a fundamental role in quantum information science.
Whereas the quantum entanglement, which can be traced back to the Einstein, Boris Podolsky and Nathan Rosen (EPR) paradox in 1935 (they argued that the description of physical reality provided by quantum mechanics was
Quantum Theory can predict certain patterns of correlation among spatially separated events correctly. This manifests
For example, if a pair of
However, it is claimed that the two
Quantum coherence presupposes the idea that an individual particle or object has wave functions that can be split into two separate waves. When the waves operate together in a coherent way, it is referred to as quantum coherence. Quantum decoherence means the loss of quantum coherence.
However, a quantum computer needs to operate coherently until the results are measured and read out. In implementing a quantum computer, a qubit and/or many entangled qubits must undergo unitary transformations before decoherence affects the qubit states as it no longer represents a unitary transformation. Quantum Theory gives an account of why ordinary macroscopic objects do not exhibit the interference behavior characteristic of quantum “superpositions”.
8. Why do these quantum effects matter?
Simply put, they are extremely useful to the future of computing and communications technology. It is due to
Quantum computing is not just “faster” than classical computing, for many types of problems the quantum computer would excel, such as code breaking. The power, which is required for code breaking, is derived from quantum computing’s use of “qubits” or “quantum bits.”
8.1 What can a quantum computer do that a classical computer cannot?
It is easy for any computer to do factoring of large numbers or multiplying two large numbers. But calculating the factors of a very large (say, 500-digit) number, on the other hand, is considered impossible for any classical computer. In 1994, a mathematician from MIT, Peter Shor, came up with the claim that if a fully working quantum computer was available, it could factor large numbers easily.
9. Areas of application
Many experts divide technologies prompted by Quantum Information Science into three application areas: (1) Quantum Sensing and metrology, (2) Communications and (3) Computing and simulation:
9.1 Quantum sensing and metrology and quantum information science
9.2 Communications, its applications and quantum information science
Quantum communications are required to increases the total computing power, especially if only processors with a few qubits are available at each network node. The most advanced application of quantum communication, and in fact of Quantum Information Processing in general, is in security. Moreover. Quantum networks provide opportunities and challenges across a range of intellectual and technical frontiers, including quantum computation and metrology.
In classical signal processing, signals traveling over fiber-optic cable about 60 miles. However, it must be retransmitted. Quantum repeaters can extend the distance the signal can be sent, but they significantly increase the complexity of the process. Communications not only must be secure, but any eavesdropping attempt will destroy the communication,
NASA developed quantum networks to support the transmission of
9.3 Computing and simulation and quantum information science
Quantum computers have enormous potential to revolutionize many areas of our society. Quantum computing provides an exponentially larger scale than classical computing, which provides advantages for certain applications.
(a) Quantum simulation refers to the use of quantum hardware to determine the properties of a quantum system, for example, determining the properties of materials such as high-temperature superconductors, and modeling nuclear and particle physics. We have seen that harnessing quantum entanglement can solve problems more efficiently.
(b) The other approach is to simulate the behavior of quantum materials and quantum systems using controlled evolution and interaction of qubits.
10. Prophiciency of the physical approach to quantum information science in dealing with “consciousness,” “freewill” and biological questions
In Part 2, we considered the physical approach to Quantum Information Science by characterizing “information” in physical terms and found it vialable. A complete physical approach to quantum information requires a robust interface among microwave photons, long-lifetime memory, and computational qubits.
It might appear to be perplexing that this physical approach to Quantum Information Science is equally proficient in dealing with “consciousness,” “freewill” and biological questions in the area known as “bioinformatics.”
10.1 Consciousness, quantum physics and quantum information science
One of the first processes based on which consciousness and quantum physics come together is through the Copenhagen interpretation of quantum physics. The central ideas of the Copenhagen interpretation were developed by a core group of quantum physics pioneers, centered around Niels Bohr’s Copenhagen Institute in the 1920s.
According to this theory, the quantum wave function collapses due to a
This is one of the reasons why the research into consciousness forged ahead in Quantum Physics and Quantum Information Science and attempts in
10.1.1 Roger Penrose
Sir Roger Penrose is an English mathematical physicist, mathematician, philosopher of science and Nobel Laureate in Physics, delved deep into at least three areas in mathematical physics: gravitational radiation, the gravitational collapse of matter in the form black holes and lastly, the modeling of the universe. He touched on many subjects, such as quantum gravity, twistor theory, a new cosmology of the cosmos. However, a scientist of such repute with the vast knowledge of fundamental areas of modern physics also saw the impact and the essential role a physical theory, such as
The idea of using quantum physics to explain human consciousness really caught genuine interest with Roger Penrose’s 1989 book,
According to Penrose consciousness
In the initial part of the book Penrose provides a summary of Classical and Quantum Physics and argues that the physical modeling of the “real world” - from Newtonian mechanics over Einstein’s relativity theory up to supersymmetry - is carried out in this Physics. However, simulation of the mind will only be possible if we understand how the missing piece of gravity radiation can be consistently included in the standard model of physics.
In the last two chapters of the book Penrose takes up his initial primary problem of modeling the human mind. To begin with Penrose gives a biophysical description of the brain and what is known about its centers and how it works. At this stage Penrose does not give a precise definition of consciousness because it is seemingly impossible. To illustrate this let us take the example of a brain, which seems to be able to register things, even when the person is
Penrose thinks that current computers will never have intelligence because of they operate under algorithmic deterministic system.
This idea is partly inspired by Penrose’s experience as a mathematician and rests on
In the last two chapters, the main concern has been as to what philosophers call the “mind–body problem”. Penrose discusses the computational procedures and the noncomputational activity he assigned to the processes of consciousness, and second, he takes recourse to yet-to-be-discovered quantum-level effects to explain consciousness.
The first book of Penrose has a follow-up book, Penrose Roger 
According to quantum mechanics, a particle can have states in which it occupies several positions at once. When we treat a system according to quantum mechanics, we have to allow for these so-called
Penrose’s collaborator, a psychologist, Stuart Hameroff also suggested that there is some biological analog of quantum computing in the brain that involves
Penrose–Hameroff theory of evolution that has made our brain the way it is and the advantage it brings to the creatures able of conscious thinking is that
10.2 ‘Free will’ and quantum information science
The significance of ‘free will’ in quantum tests, to find a quantum perspective on “free will” leads to the issue of
However, brain’s electrical activity correlating with conscious perception of a stimulus, apparently shows that it can occur
Today, there is little doubt that our
I spite of these developments, a group of practitioners of science and technology strongly believe that while all the wonderful abilities of some animals, including consciousness and goal-directed behavior, are indeed the result of mechanistic processes, there is no way human consciousness and choice (and possibly that of some of the higher animals) can simply be the result of an essentially Newtonian physics.
If scientists are able to
10.2.1 Quantum indeterminacy and free will
The idea of
10.3 Biological issues/ “quantum bio-informatics” and quantum information science
There are two important large-scale activities that use
For the future of bioinformatics a key research question would be as to how to computationally compare complex biological observations, such as gene expression patterns and protein networks. Bioinformatics converts
Of course Quantum Mechanics is the fundamental theory that describes the properties of subatomic particles, atoms, molecules, molecular assemblies. However, Quantum Mechanics operates on the nanometer and sub-nanometer scales. This forms the basis of fundamental life processes such as photosynthesis, respiration and vision. The fundamental claim by Quantum Mechanics is that all objects have wave-like properties and when they interact, quantum coherence describes the correlations between the physical quantities describing such objects that have a wave-like nature.
In Quantum Information Science
Surprisingly the physical approach to Quantum Information Science is equally significant and apt in dealing with “consciousness,” “freewill” and “bioinformatics.” Penrose and his collaborator, Stuart Hameroff, maintained that human intelligence is far more subtle than ‘artificial intelligence’ and suggested a biological analog to quantum computation involving microtubules. In neurons, microtubules (which inhabit in neurons in the brain) help control the strength of synaptic connections. In the Penrose-Hameroff theory of Orchestrated Objective Reduction, known as Orch-OR, the moments of conscious awareness are orchestrated by the microtubules in our brains, which, they believe, have the capacity to store and process information and memory. Orch OR Model and biological theories of mind are important in the area known as “bioinformatics.”
I have no words to express my sincere and deep gratitude to my Editor from IntechOpen for a full chapter Review consisting of meticulous and painstaking criticisms, and insightful suggestions which enabled me to bring the paper to its present somewhat decent shape. I also cannot refrain myself from mentioning the name, Mrs. Chaitali Gupta, my wife, whose care and constant encouragement to complete the paper made it possible for me to work hard and finish it during the time of pandemic and devastations by an extremely severe cyclonic storm arising from the Arabian sea, called Tauktae, and when I was not keeping well. I must convey my sincere appreciation to Ms. Madhavi Rao for going out of her way in helping me to bringing the paper in its present form.