相关论文: Coherence and interactions in diffusive systems
The decoherence of quantum states defines the transition between the quantum world and classical physics. Decoherence or, analogously, quantum mechanical collapse events pose fundamental questions regarding the interpretation of quantum…
We investigate flux qubits driven by a biharmonic magnetic signal, with a phase lag that acts as an effective time reversal broken parameter. The driving induced transition rate between the ground and the excited state of the flux qubit can…
We report a complete analytical expression for the one-loop correction to the ac conductivity $\sigma(\omega)$ of a disordered two-dimensional electron system in the diffusive regime. The obtained expression includes the weak localization…
A review of coherent phenomena in photoexcited semiconductors is presented. In particular, two classes of phenomena are considered: On the one hand the role played by optically-induced phase coherence in the ultrafast spectroscopy of…
Quantum interference effects and resulting quantum corrections of the conductivity have been intensively studied in disordered conductors over the last decades. The knowledge of phase coherence lengths and underlying dephasing mechanisms…
In condensed matter systems, coherent backscattering and quantum interference in the presence of time-reversal symmetry lead to well-known phenomena such as weak localization (WL) and universal conductance fluctuations (UCF). Here we use…
The Aharonov-Casher effect is the analogue of the Aharonov-Bohm effect that applies to neutral particles carrying a magnetic moment. This can be manifested by vortices or fluxons flowing in trajectories that encompass an electric charge.…
The response of an arbitrary closed quantum system to a partially coherent electric field is investigated, with a focus on the transient coherences in the system. As a model we examine, both perturbatively and numerically, the coherences…
The effects of fluctuating boundaries on a superposition state of a quantum particle in a box is studied. We consider a model in one space dimension in which the initial state is a coherent superposition of two energy eigenstates. The…
Manifestations of quantum coherence in the electronic conductance through nearly closed quantum dots in the Coulomb blockade regime are addressed. We show that quantum coherent tunneling processes explain some puzzling statistical features…
Generic quantum interference effects occuring in 1D-quasicrystals are reviewed with emphasis on the joint effect of phason disorder on electronic localization and propagation modes. In close conjunction with properties of real materials,…
There exist some boundary-driven open systems with diffusive dynamics whose particle current fluctuations exhibit universal features that belong to the Edwards-Wilkinson universality class. We achieve this result by establishing a mapping,…
The decoherence rate of a quantum dot coupled to a fluctuating environment described by a normal-metal superconductor junction is considered. The density-density correlator at low frequencies constitutes the kernel which enters the…
Coherent states provide a natural connection of quantum systems to their classical limit and are employed in various fields of physics. Here we derive general systematic expansions, with respect to quantum parameters, of expectation values…
We report the investigation of the dynamic conductance fluctuation of disordered mesoscopic conductors including 1D, 2D and quantum dot systems. Our numerical results show that in the quasi-ballistic regime the average emittance is negative…
Employing a real time effective action formalism we analyze electron transport and current fluctuations in comparatively short coherent conductors in the presence of electron-electron interactions. We demonstrate that, while Coulomb…
Quantum coherence and phase transitions are studied in a finite one-dimensional Bose--Hubbard model using exact diagonalization under thermal fluctuations, a Stark potential, and disorder. The condensate fraction, superfluid fraction,…
Quantum coherence profoundly alters classical thermodynamic expectations by modifying the structure and accessibility of probability distributions. Classically, transitions to lower-entropy states (local second-law violations) are…
The density of states of the disordered s-wave superconductor is calculated perturbatively. The effect of Coulomb interaction on diffusively moving electrons in the normal state has been known before, but in the superconducting state both…
The population decay due to a small opening in an otherwise closed cavity supporting chaotic classical dynamics displays a quantum correction on top of the classical exponential form, a pure manifestation of quantum coherence that acquires…