The physics of dynamic resonant tunneling is investigated.
Part of the book: Research Advances in Quantum Dynamics
The law of association, which is a generalization of Ricardo's law of comparative advantage, is one of the most fundamental laws in economics, which explains the benefits of international trade in the macroscopic level and the division of labour in the microscopic one. However, the derivation of the law is traditionally based on aggregate production criterions rather than on the producers' subjective preferences. An economic law, which ignores subjective preferences cannot be regarded as a fundamental one. In this chapter, a subjective analysis of the law is presented, to the best of our knowledge, for the first time. It is shown that when subjective considerations are introduced the tendency to trade can be reduced. An algorithm is presented to illustrate the dynamics of the process, in which the information regarding the subjective preferences is transferred via the previous trading prices. Furthermore, the effect of specialization on the production frontiers, which is absent in most economics derivations of the law, is taken under consideration. It is shown that even if both producers are identical a non-trading state is unstable. It is therefore shown that counter to mainstream thinking, comparative advantage is neither necessary nor is it a sufficient condition for trading.
Part of the book: Emerging Issues in Economics and Development
The way data is lost from the wavefunction in quantum dynamics is analyzed. The main results are (A) Quantum dynamics is a dispersive process in which any data initially encoded in the wavefunction is gradually lost. The ratio between the distortion’s variance and the mean probability density increases in a simple form. (B) For any given amount of information encoded in the wavefunction, there is a time period, beyond which it is impossible to decode the data. (C) The temporal decline of the maximum information density in the wavefunction has an exact analytical expression. (D) For any given time period there is a specific detector resolution, with which the maximum information can be decoded. (E) For this optimal detector size the amount of information is inversely proportional to the square root of the time elapsed.
Part of the book: Advanced Technologies of Quantum Key Distribution
An exact model for a single atom transistor was developed. Using two simplifying assumptions (1) that the device is restricted to a narrow conducting wire and (2) that the atom can be simulated by a point impurity potential, the model can be simplified considerably and an exact analytical solution can be derived. Thus, analytical solution is approximated to a close-form solution in three important regimes: at the vicinity of the resonance energy (near the maximum peak), at the vicinity of the inverse resonance, i.e., Fano resonance (near the minimum), and at the threshold energy where a universal transmission pattern appears. Finally, physical values are applied to demonstrate that this device can operate as a transistor, when it is calibrated to work at the vicinity of its maximum and minimum points.
Part of the book: Nonmagnetic and Magnetic Quantum Dots
In this chapter, a simple market model is presented to illustrate how random entrepreneurial activity can be responsible for the establishment of economic equilibria without the assumption of perfect knowledge. In this model it is assumed that the entrepreneurs (both traders and producers) have no information regarding the other entrepreneurs’ preferences, wealth, or production skills. The only information they have is the past transaction prices, and yet this information is sufficient for the market to reach equilibrium price. Equilibrium is not a stationary process on the microscopic level. It is a process, which consists of interactions between entrepreneurs, who act randomly without insight. Consequently, the market price continuously oscillates randomly around the equilibrium values. The higher the risk the producers are willing to take, the more stable is the equilibrium. When entrepreneurial actions are depressed, the market may drift from its optimal point. This model also investigates the more realistic scenario, in which, due to specialization, the production boundary frontiers are convex (instead of linear). It is shown that in this case, the drifts are suppressed and the optimal equilibrium is more stable. Moreover, the amount of risk aversion has a clear effect on the production growth of the economy. The lower the risk aversion is, the higher is the growth rate of the economy.
Part of the book: Entrepreneurship
In this chapter, a generalization of the Ricardian model of international trading is presented. Unlike the original Ricardian analysis, the presented model takes into account the producers entrepreneurial activities, their specialization factor (the improvement factor in production due to specialization) and the countries taxes (tariffs). The main result of this model is that for a given entrepreneurial activity culture and a given specialization factor, there exists a critical taxation level, above which specialization and all entrepreneurial activities are suppressed and international commerce is ceased. The transition from a working international market to a trade-less one is an abrupt one and resembles a phase transition.
Part of the book: Trade and Global Market
Bitcoin and other cryptocurrencies received a lot of criticism during the last 9 years. It is not surprising that this criticism came from organizations that are threatened by the crypto revolution (banks, government, central banks, finance companies, etc.). Nevertheless, it is very surprising to hear criticism from economics schools, which oppose central banking and advocate free choice in currencies (such as the Austrian school of economics). Unlike the ordinary criticism (that Bitcoin is a scam, a bubble, etc.), which can easily be refuted, the criticism of part of the Austrian school economists is based on interesting arguments, which requires a different level of explanation. For example, it was claimed that Bitcoin should be worthless; otherwise, it contradicts Mises’ regression theorem. The object of the chapter is twofold: first to explain why the criticism is unfounded and second to analyze the origin of the value of Bitcoin and other cryptocoins from the perspective of the Austrian school of economics. In particular, it is explained that Bitcoin does not contradict the regression theorem for two reasons. First, the initial value estimation can be a random event, and second, the Bitcoin network (even now) has a nonmonetary value.
Part of the book: Blockchain and Cryptocurrencies
A simple single-atom transistor configuration is suggested. The transistor consists of only a nanowire, a single-point impurity (the atom), and an external capacitor. The transistor gate is controlled by applying a transverse voltage on the capacitor. The configuration does not rely on tunneling current and, therefore, is less sensitive to manufacturing processes since it requires less accuracy and fewer production processes. Moreover, unlike resonant-tunneling devices, the proposed transistor configuration does not suffer from a compromise between high speed and high extinction ratio. In fact, it is shown that this transistor can be extremely fast, without affecting the signal’s extinction ratio, which can be as high as 100%.
Part of the book: Quantum Electronics