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

Abstract

Electrical manipulation and read-out of quantum states in zero-dimensional nanostructures by nano-gap metal electrodes is expected to bring about innovation in quantum information processing. However, electrical tunability of the quantum states in zero-dimensional nanostructures is limited by the screening of gate electric fields. Here we demonstrate a new way to realize wide-range electrical modulation of quantum states of single self-assembled InAs quantum dots (QDs) with a liquid-gated electric-double-layer (EDL) transistor geometry. The efficiency of EDL gating is 6-90 times higher than that of the conventional solid gating. The quantized energy level spacing is modulated from B15 to B25 meV, and the electron g-factor is electrically tuned over a wide range. Such a field effect tuning can be explained by the modulation in the confinement potential of electrons in the QDs. The EDL gating on the QDs also provides potential compatibility with optical manipulation of single-electron charge/spin states.

Endeavor of Iontronics: From Fundamentals to Applications of Ion‐Controlled Electronics

“…The size of the InAs QD used was about 70 nm × 110 nm × 25 nm. g) Coulomb stability diagrams measured at 3.5 K for V EDL = −1 V; −0.5 V; −0.2 V; and −0.1 V. d–g) Reproduced with permission . Copyright 2013, Nature Publishing Group.…”

“…The use of EDLTs has been proven to be more efficient than that of conventional solid‐gated FETs even in the case of the single‐quantum‐dot devices. Shibata et al performed manipulation and read‐out of quantum states in self‐assembled InAs quantum dots, that coupled into nanogap metal electrodes, using the EDLT device with the [DEME][TFSI] ionic liquid (Figure d–g) . They demonstrated a large modulation of the QD electronic states by obtaining a Coulomb stability diagram with multiple Coulomb diamonds displaying the shell structure of the InAs QDs.…”

“…In addition, the EDL gating also affects the electron spin properties in the QDs through the observation of a gate‐voltage‐dependent g ‐factor. The observed field effects can be explained by the change of the surface‐depletion thickness of QDs, resulting in a change in the confinement potential of the material …”

Binary atomic silicon logic

“…known to pose additional challenges 23 . The prospect to partially circumvent these issues was reported in studies of silicon dangling bonds (DBs), i.e., unsatisfied bonds, on the otherwise hydrogen-terminated silicon surface (H-Si) 15 .…”

Chitosan solid electrolyte as electric double layer in multilayer MoS2 transistor for low‐voltage operation

“…At the same time, in recent years, an alternative approach for improving dielectric‐channel coupling that has attracted a lot of interest is the utilization of electric double layers (EDLs) for top gating, using ionic liquids as gate dielectrics . Compared to traditional transistors, the EDL in this kind of device acts like a nanogap capacitor (typical thickness of EDL is ∼1.0 nm), and consequently a high gate capacitance (∼μF/cm 2 ) can be easily obtained due to such EDL effect .…”