Magnetic-field-modulated terahertz absorption spectra of a quantum ring

Abstract

The magnetic-field-modulated terahertz absorption spectra of a real GaAs quantum ring (QR) are studied by calculating the photon-participated tunneling current through the QR. We find that the absorption of photons can lead to a reduction in the tunneling current and this manifests as dips in the current versus magnetic field curves. There exists a saturation value for the depth of the current dip, which is described by a simple formula. A full width at half maximum less than 10GHz can be reached for current dips induced by terahertz fields for Rabi frequencies smaller than 2.5GHz. Our study provides a possible way to realize tunable detection of terahertz fields.

Kinetics of the evolution of InAs/GaAs quantum dots to quantum rings: A combined x-ray, atomic force microscopy, and photoluminescence study

“…Infrared photodetectors based on QRs have the potential of high response speed, low dark and noise current, and it also exhibits the far infrared wavelength detection ability. [9][10][11][12] A number of experimental studies were concerned with the formation mechanism of InAs/GaAs QRs. [13][14][15][16] The conventional method for the formation of InAs/GaAs QRs is a capping and annealing procedure, in which a thin GaAs layer is deposited on top of the InAs QDs followed by 30 s of annealing in As 2 flux.…”

Impact of a circularly polarized cavity photon field on the charge and spin flow through an Aharonov–Casher ring

“…It is interesting to note that the photon field couples directly to the spin via Eqs. (8), (9) and (6). For reasons of comparison and to determine the photocurrents, we also consider results without photons in [32,33,54] by letting the photon cavity be much larger than the quantum ring (this assumption is used in the derivation of the vector potential, Eq.…”

“…It is interesting to note that the photon field couples directly to the spin via Eqs. ( 8), ( 9) and (6). For reasons of comparison and to determine the photocurrents, we also consider results without photons in 2).…”

“…Furthermore, the rotational symmetry of the ring resembles the characteristics of a circularly polarized photon field suggesting a strong lightmatter interaction between single photons and the ring electrons. Circularly polarized light emission [5] and absorption [6] has been studied for quantum rings. Moreover, circularly polarized light has been used to generate persistent charge currents in quantum wells [7] and quantum rings [8,9,10,11].…”

Nonlinear transport in coupled quantum dots: A stationary probability approach

“…QD and coated-QD nanoparticles have been applied in biodetection by using the fluorescence resonance transfer [10][11][12] . Many peculiar quantum transport properties have been found in the QDs, for example, Coulomb blockade effect [13] , due to Hubbard interaction among the charged carriers [3,14] , photon-assisted transport properties [15][16][17][18] , Kondo effect in the quantum dots due to the coupling of local degenerate state to the mobile electron reservoirs [19][20][21] . The optical absorption [22] and electric capacitance spectra [23] have been studied in QD within the multiple-electron configuration, the luminescence in porous silicon can be interpreted by the QD model taking into account of the interfacial-confined polarons [24] .…”