Aharonov-Bohm quantum rings in high-Qmicrocavities

Abstract

A single-mode microcavity with an embedded Aharonov-Bohm quantum ring, which is pierced by a magnetic flux and subjected to a lateral electric field, is studied theoretically. It is shown that external electric and magnetic fields provide additional means of control of the emission spectrum of the system. In particular, when the magnetic flux through the quantum ring is equal to a half-integer number of the magnetic flux quantum, a small change in the lateral electric field allows tuning of the energy levels of the quantum ring into resonance with the microcavity mode providing an efficient way to control the quantum ring-microcavity coupling strength. Emission spectra of the system are calculated for several combinations of the applied magnetic and electric fields.

Coupled Collective and Rabi Oscillations Triggered by Electron Transport through a Photon Cavity

“…The transport of electrons through quantum dots assisted by up to four photons in the teraherz frequency range has been observed [1], and double quantum dots have been used to detect single-photons from shot-noise in electron transport through a quantum point contact [2]. The properties and control of atomic or electronic systems in photonic cavities is a common theme in the research effort of many teams working on various aspects of quantum cavity electrodynamics and related fields [3][4][5][6][7][8][9][10]. The non-local single-photon transport properties of two sets of double quantum dots within a photon cavity has recently been modeled [11], and also a pump-probe scheme for electron-photon dynamics in a hybrid conductor-cavity system with one electron reservoir [12].…”

Nanohelices as superlattices: Bloch oscillations and electric dipole transitions

“…In the limit d → 0 we recover the standard particle on a ring. Most notably, our electron on a helix system is equivalent to an electron on a quantum ring pierced by a magnetic flux and subject to a lateral electric field [52][53][54][55]. In the Aharonov-Bohm ring problem, the role of the quasimomentum in the nanohelices is formally played by a magnetic flux in the units of the flux quantum.…”

Tuning terahertz transitions in a double-gated quantum ring

“…The shapes of these double well potentials are therefore intrinsic to the specific heterostructure and, while robust, offer limited ability to manipulate the shapes of the potentials without the use of large external fields. Promising candidates also exist in the form of nonsimply connected nanostructures, such as carbon nanotubes [9][10][11][12], double-layer graphene [13], or quantum rings [14][15][16]. The appeal in using these latter structures for THz devices, in lieu of those former, lies in their greater tunability with external fields.…”