The Contribution of Hot Electron Spin Polarization to the Magnetotransport in a Spin-Valve Transistor at Finite Temperatures

The effect of spin mixing due to thermal spin waves and temperature dependence of hot electron spin polarization to the collector current in a spin-valve transistor has been theoretically explored. We calculate the collector current as well as the temperature dependence of magnetocurrent at finite temperatures to investigate the relative importance of spin mixing and hot electron spin polarization. In this study the inelastic scattering events in ferromagnetic layers have been taken into account to explore our interests. The theoretical calculations suggest that the temperature dependence of hot electron spin polarization has substantial contribution to the magnetotransport in the spin-valve transistor.Comment: 8 pages and 6 figure

COVID-19 Impact on Indian Economy and Health: The Emergence of Corona-Economics

The Novel Corona virus, popularly known as COVID-19, has crossed all borders in a very short period of time and has spared no continent except Antarctica. Some advanced countries are affected more severely than others; with United States of America, Spain, Italy, China, Germany, France and UK being the worst affected of all with a few more are joining them soon. Several countries has locked-down to prevent further spread of the virus. This resulted in severe economic and health impacts on the public at large

Non-Destructive Discrimination of arbitrary set of orthogonal quantum states by NMR using Quantum Phase Estimation

An algorithm based on quantum phase estimation, which discriminates quantum states nondestructively within a set of arbitrary orthogonal states, is described and experimentally verified by a NMR quantum information processor. The procedure is scalable and can be applied to any set of orthogonal states. Scalability is demonstrated through Matlab simulation

Singlet state creation and Universal quantum computation in NMR using Genetic Algorithm

Experimental implementation of a quantum algorithm requires unitary operator decomposition. Here we treat the unitary operator decomposition as an optimization problem and use Genetic Algorithm, a global optimization method inspired by nature's evolutionary process for operator decomposition. As an application, we apply this to NMR Quantum Information Processing and find a probabilistic way of doing universal quantum computation using global hard pulses. We also demonstrate efficient creation of singlet state (as a special case of Bell state) directly from thermal equilibrium using an optimum sequence of pulses

How Substitutable is Natural Capital?

One of the recurring themes in the sustainability literature has been the legitimacy of using an economic framework to account for natural resources. This paper examines the potential for substituting between different inputs in the generation of income, where the inputs include natural resources such as land and energy resources. A nested CES production function is used to allow flexibility in the estimated elasticities of substitution. Also, with this specification, natural resources and other inputs are combined in different levels of the function, thus allowing for different levels of substitutability. Institutional and economic indicators are also incorporated in the production function estimated. Results show that the elasticities derived from functions involving land resources were generally around one or greater. Furthermore, changes in trade openness and private sector investment have a statistically significant and direct relationship with income generation. No statistically significant relationship between income and any of the institutional indicators was found.Wealth accounting, Natural resources, Nested CES production function

Quantum Critical Environment Assisted Quantum Magnetometer

A central qubit coupled to an Ising ring of $N$ qubits, operating close to a critical point is investigated as a potential precision quantum magnetometer for estimating an applied transverse magnetic field. We compute the Quantum Fisher information for the central, probe qubit with the Ising chain initialized in its ground state or in a thermal state. The non-unitary evolution of the central qubit due to its interaction with the surrounding Ising ring enhances the accuracy of the magnetic field measurement. Near the critical point of the ring, Heisenberg-like scaling of the precision in estimating the magnetic field is obtained when the ring is initialized in its ground state. However, for finite temperatures, the Heisenberg scaling is limited to lower ranges of $N$ values.Comment: 10 pages, 9 figure