Related papers: Resonance quantum switch: search for working param…
The concept of thermal ratchets is extended to the system governed by quantum mechanics. We study a tight-binding model with an asymmetric periodic potential contacting with a heat bath under an external oscillating field as a specific…
Reducing the thermal noises in microwave (MW) resonators can bring about significant progress in many research fields. In this study, we consider using three-level or four-level systems as "quantum refrigerators" to cool down MW resonators…
In this work, we show that the quantum compass model on an square lattice can be mapped to a fermionic model with local density interaction. We introduce a mean-field approximation where the most important fluctuations, those perpendicular…
We study the possibility of implementing a quantum switch and a quantum memory for matter wave lattice solitons by making them interact with "effective" potentials (barrier/well) corresponding to defects of the optical lattice. In the case…
This thesis focuses on quantum information processing using the superconducting device, especially, on realizing quantum gates and algorithms in open quantum systems. Such a device is constructed by transmon-type superconducting qubits…
Navigating the intricacies of thermal management at the quantum scale is a challenge in the pursuit of advanced nanoscale technologies. To this extent, theoretical frameworks introducing minimal models mirroring the functionality of…
We investigate the distribution of the electron density and the potential in a quantum wire coupled to reservoirs, treating this structure as a unified quantum system and taking into account the Coulomb interaction of electrons. The…
An electron inside liquid helium forms a bubble of 17 \AA in radius. In an external magnetic field, the two-level system of a spin 1/2 electron is ideal for the implementation of a qubit for quantum computing. The electron spin is well…
The longitudinal resistivity at transitions between integer quantum Hall states in two-dimensional electrons confined to AlAs quantum wells is found to depend on the spin orientation of the partially-filled Landau level in which the Fermi…
When driven by a potential bias between two finite reservoirs, the particle current across a quantum system evolves from an initial loading through a coherent, followed by a metastable phase, and ultimately fades away upon equilibration. We…
A quantum-mechanical formulation of energy transfer between closely-spaced surfaces is given. Coupling between the two surfaces arises from the atomic dipole-dipole interaction involving transverse-photon exchange. The exchange of photons…
A reconfigurable logic gate is proposed in a two-dimensional double quantum wire system with a coupling window enabled by a Rashba field. Manipulating the spin states of incoming electrons several quantum logic gates (OR, AND, XOR, CNOT)…
We propose that the recently realized T-shaped semiconductor quantum wires (T-wires) could be exploited as three-terminal quantum interference devices. T-wires are formed by intersecting two quantum wells (QWs). By use of a scattering…
Radio frequency cryogenic switches are a critical enabling technology for quantum information science for both calibration and high throughput testing of samples. Traditionally, solenoid-based switches have been used [1,2], but a transition…
We clarify the role of quantum-well states in magnetic trilayer systems from majority carrier in the ferromagnetic and all carriers in the antiferromagnetic configurations. In addition to numerical and analytic calculations, heuristic…
We propose a quantum heat engine composed of two superconducting transmission line resonators interacting with each other via an optomechanical-like coupling. One resonator is periodically excited by a thermal pump. The incoherently driven…
Quantum critical systems derive their finite temperature properties from the influence of a zero temperature quantum phase transition. The paradigm is essential for understanding unconventional high-Tc superconductors and the non-Fermi…
A central building block of a heat engine is the working fluid, which mediates the conversion of heat into work. In nanoscale heat engines, the working fluid can be a quantum system whose behavior and dynamics are non-classical. A…
If the states of spins in solids can be created, manipulated, and measured at the single-quantum level, an entirely new form of information processing, quantum computing, will be possible. We first give an overview of quantum information…
We investigate the confined states and transport of three-dimensional Weyl electrons around a one-dimensional external rectangular electrostatic potential. Confined states with finite transverse wave vector exist at energies higher than the…