We study some general properties of coupled quantum systems. consider simple interactions between two copies identical Hamiltonians such as the SYK model, Pauli spin chains with random magnetic field and harmonic oscillators. Such couplings make ground states close to thermofield double uncoupled Hamiltonians. For we push numerical computation further towards thermodynamic limit so that an extr...

There are several reasons to be interested in quantum, nonabelian monopoles. First, if confinement of QCD is a sort of dual superconductor, it is likely to be one of nonabelian variety. Then the effective degrees of freedom involve nonabelian, and not, better understood abelian monopoles. Second, the phenomenon of confinement has to do with fully quantum mechanical, and not semi-classical, beha...

The confinement induced resonance provides an indispensable tool for the realization of the low-dimensional strongly interacting quantum system. Here, we investigate the confinement induced resonance in spin-orbit coupled cold atoms with Raman coupling. We find that the quasi-bound levels induced by the spin-orbit coupling and Raman coupling result in the Feshbach-type resonances. For sufficien...

Abstract--We have theoretically investigated the effect of shape anisotropy and size on electronic structure of GaAs/AlGaAs quantum dots (QDs). The quantum dot is modeled by anisotropic parabolic confinement potential in the plane perpendicular to the growth direction while the confinement along the growth direction is modeled as quantum well potential. The Luttinger Hamiltonian formulation has...

Development of Si-based light emitter has been eagerly anticipated in Si photonics. However, its realization is difficult because group IV semiconductors such as Si and Ge are indirect-transition semiconductors. Si or Ge quantum dots (QDs) on Si substrates have drawn much attention as Si-based light emitting materials because their optical transition probability can be enhanced by their quantum...

Ballistic Electron Emission Microscopy (BEEM) and finite-element electrostatic modeling were used to quantify how “small-size” effects modify the energy barrier at metal/semiconductor nanostructure nanocontacts, formed by making Schottky contacts to cleaved edges of GaAs quantum wells (QWs). The Schottky barrier height over the QWs was found to systematically increase with decreasing QW width, ...

In the presence of spin-orbit coupling and inversion symmetry of the lateral confinement potential a single electron does not exhibit matrix Berry phases in quasi-two-dimensional semiconductor quantum dots. In such a system we investigate whether many-body correlation effects can lead to finite matrix Berry phases. We find that the transformation properties of many-electron wavefunctions under ...

Low dimensional structures have come a long way from being mere examples of applied quantum mechanics tv widespread applications in many modem devices and instruments. Quantum well, quantum cascade and quantum dot lasers make use of the very fundamental idea of carrier confinement within dimenswns that match their de Broglie wavelength. Quantum well lasers are used in many modern optoelectronic...