Theoretical and Condensed Matter Physics

Biography

Biography: Eliade Stefanescu

Abstract

Recently, we conceived a semiconductor structure converting environmental heat into electromagnetic energy and, further, into electric energy: while a current I is injected in the device, a super radiant field is generated by quantum transitions of electrons from the n-zones to the p-zones. We notice that this current enhances the lower states of the ohmic contacts between the n-p super radiant junctions, while the upper states of these contacts are depleted. This makes these contacts become colder, the current I traversing these contacts by thermal excitations of electrons, on the account of the heat absorption from the surrounding zones. This is a complex process based on the quantum dynamics of three coupled physical systems: (1) the active electrons in the quantum wells of the super radiant junctions, (2) the electromagnetic field in the device cavity, and (3) the optical vibrations of the crystal lattice, leading to an approximately 3 times variation of the field propagation velocity, according to the crystal refractive index. The dynamics of these systems includes an important dissipative component due to the couplings to the other electrons and to the mechanical vibrations of the crystal. We describe the dissipative quantum dynamics of the three systems by quantum master equations with explicit microscopic coefficients depending on the physical characteristics of the device. We understand the electron and electromagnetic field dynamics in the framework of a unitary relativistic quantum theory. In this theory, a quantum particle is described by wave packets in the two spaces of the coordinates and momenta, of a form providing the Hamilton equations as group velocities of the two wave packets, which include the Lagrangian instead of the Hamiltonian in the conventional wave functions. Unlike the classical relativistic principle of the light velocity consistency, we consider a relativistic quantum principle of invariance of the time dependent phase of a quantum particle.