Coherent quantum transport in narrow constrictions in the presence of a finite-range longitudinally polarized time-dependent field

Abstract

We have studied the quantum transport in a narrow constriction acted upon by a finite-range longitudinally polarized time-dependent electric field. The electric field induces coherent inelastic scatterings which involve both intra-subband and inter-sideband transitions. Subsequently, the dc conductance G is found to exhibit suppressed features. These features are recognized as the quasibound-state (QBS) features which are associated with electrons making transitions to the vicinity of a subband bottom, of which the density of states is singular. Having valley-like instead of dip-like structures, these QBS features are different from the G characteristics for constrictions acted upon by a finite-range time-modulated potential. In addition, the subband bottoms in the time-dependent electric field region are shifted upward by an energy proportional to the square of the electric field and inversely proportional to the square of the frequency. This effective potential barrier is originated from the square of the vector potential and it leads to the interesting field-sensitive QBS features. An experimental set-up is proposed for the observation of these features.

Time-dependent magnetotransport in an interacting double quantum wire with window coupling

“…Quantum transport in an open system acted upon by a time-dependent potential has been considered in different systems such as time-dependent quasibound-state features, 31,32 quantum pump in Luttinger liquids, 33 photon-associated transport in nanostructures, [34][35][36] the Kondo effect in a double quantum dot−quantum wire coupled system, 37 ac-field control of spin current, 38,39 and transient current dynamics in nanoscale junctions. 40,41 The rapid progress of nanoelectronics and information technologies has prompted intense interest in exploiting the quantum interference transport properties of correlated electrons, in which the coupling between the mesoscopic subsystem could be manipulated by an applied external magnetic field.…”

Optimization of electron pumping by harmonic mixing

“…An early example of a similar strategy is the heuristic approach to understand the effect of timeperiodic driving on the current voltage characteristics of superconductor-insulator-superconductor junctions that has been given by Tien and Gordon [11]. More recently, Floquet scattering theory has been used to get expressions for transmission probabilities [12][13][14][15][16][17][18]. In addition, Kim [19] as well as Moskalets and Büttiker [20] exploited this method for considering an electronic pump consisting of two oscillating δ-peaks.…”

“…In addition, Kim [19] as well as Moskalets and Büttiker [20] exploited this method for considering an electronic pump consisting of two oscillating δ-peaks. In [12][13][14][15][17][18][19][20]] the scattering matrix is determined from the matching conditions of the wave function. Furthermore, electron-pumping scenarios have been treated with the help of Floquet theory using an equation-of-motion approach in the Heisenberg picture [21,22], solving the master equation [22][23][24], or using non-equilibrium Green's functions [25][26][27].…”

Non-Adiabatic Current Excitation in Quantum Rings

“…Time-dependent or radiation induced phenomena in various mesoscopic electron systems has attracted considerable interest over the past few years [1,2,3,4,5]. These high-frequency modulated nanostructures, formed in a two-dimensional electron gas (2DEG) by applying appropriate confinement, are important both in connection with device application and can function as convenient samples to probe the properties of electron systems in reduced dimensions.…”