Photon-Assisted Tunneling through Self-Assembled InAs Quantum Dots in the Terahertz Frequency Range

Abstract

We have investigated terahertz (THz) photon-assisted tunneling in single self-assembled InAs quantum dots (QDs). Two types of photon-assisted tunneling processes have been observed in the THz range: ground state resonance and photon-induced excited state resonance, depending on the relative magnitude between the orbital quantization energy of the QDs and the THz photon energy. Furthermore, we could realize a very high coupling efficiency between THz waves and QDs and observed multiphoton absorption up to the fourth-order during the tunneling process, resulting in almost complete lifting of the Coulomb blockade.

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].…”

Large modulation of zero-dimensional electronic states in quantum dots by electric-double-layer gating

“…Furthermore, the use of optically transparent ionic liquids as the gate dielectrics (Fig. 1b) potentially allows us to optically manipulate single-electron charge/spin states in QDs 6 , which is in clear contrast with the conventional metal top-gate structures, which block incoming light and hinder optical manipulation 33 .…”

“…Electron tunnelling through single self-assembled InAs quantum dots (QDs) coupled to nano-gap metal electrodes has been intensively investigated. To date, a variety of remarkable properties of the InAs QD transistors has already been revealed, such as artificial-atom properties 11,12 , electrically tunable large g-factors 13 and spin-orbit interaction 5,14,15 , and optical pumping of carriers in the terahertz frequency range 6 . However, electrical tuning of the electronic states in the QDs over a wide range has so far been elusive and remains as a great challenge.…”

“…With this technological trend extrapolated, the device miniaturization will soon meet its physical limits 1 . Therefore, the use of bottom-up nanostructures as an active channel of transistors becomes increasingly important and attracts considerable attention for their prospective applications, especially to quantum information processing [2][3][4][5][6] . One of the promising techniques for electrical access to extremely small bottom-up nanostructures is the use of nano-gap metal electrodes [7][8][9][10][11] .…”

Dynamical Coulomb blockade of tunnel junctions driven by alternating voltages

“…It has found numerous applications to problems as diverse as atomic-sized contacts 7 , artificial atoms 8 , Josephson and Majorana qubits 9,10 , current sources 11 and the quantum measurement of work 12 . While standard P (E) theory 1-3 considers circuits with constant voltage bias, more recent work [13][14][15][16][17][18] has addressed nanostructures driven by alternating voltages inspired by nanoelectronic experiments in the GHz range and above [19][20][21] .…”