English
Related papers

Related papers: Charge detection in gate-defined bilayer graphene …

200 papers

A double quantum dot charge detector, with one dot Coulomb coupled to the electron to be detected and the other modulated by a time-dependent plunger voltage, is analyzed in a minimal model. The signal and noise of the detector are…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Tamas Geszti , Jozsef Zsolt Bernad

We report the fabrication of electrostatically defined nanostructures in encapsulated bilayer graphene, with leakage resistances below depletion gates as high as $R \sim 10~$G$\Omega$. This exceeds previously reported values of $R =~$10 -…

We report on the realization of a coupled quantum dot (QD) system containing two single QDs made in two adjacent InAs nanowires. One QD (sensor QD) is used as a charge sensor to detect the charge state transition in the other QD (target…

Mesoscale and Nanoscale Physics · Physics 2022-10-07 Jingwei Mu , Weijie Li , Shaoyun Huang , Dong Pan , Yuanjie Chen , Ji-Yin Wang , Jianhua Zhao , H. Q. Xu

The implementation of a quantum computer requires a qubit-specific measurement capability to read-out the final state of a quantum system. The model of spin dependent tunneling followed by charge readout has been highly successful in…

Mesoscale and Nanoscale Physics · Physics 2015-04-07 M. F. Gonzalez-Zalba , A. J. Ferguson , S. Barraud , A. C. Betz

We demonstrate electron redistribution caused by magnetic field on a single quantum dot measured by means of a quantum point contact as non-invasive detector. Our device which is fabricated by local anodic oxidation allows to control…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 C. Fricke , M. C. Rogge , B. Harke , M. Reinwald , W. Wegscheider , F. Hohls , R. J. Haug

We analyze charging effects in graphene quantum dots. Using a simple model, we show that, when the Fermi level is far from the neutrality point, charging effects lead to a shift in the electrostatic potential and the dot shows standard…

Mesoscale and Nanoscale Physics · Physics 2008-02-06 B. Wunsch , T. Stauber , F. Guinea

We implement circuit quantum electrodynamics (cQED) with quantum dots in bilayer graphene, a maturing material platform for semiconductor qubits that can host long-lived spin and valley states. The presented device combines a high-impedance…

We investigate the application of nanoscale topgates on exfoliated bilayer graphene to define quantum dot devices. At temperatures below 500 mK the conductance underneath the grounded gates is suppressed, which we attribute to nearest…

Mesoscale and Nanoscale Physics · Physics 2018-11-15 André Müller , Bernd Kaestner , Frank Hohls , Thomas Weimann , Klaus Pierz , Hans W. Schumacher

We investigate experimentally the quantum coherence of an electronic two-level system in a double quantum dot under continuous charge detection. The charge-state of the two-level system is monitored by a capacitively coupled single quantum…

We present an electronic transport experiment in graphene where both classical and quantum mechanical charge detector back-action on a quantum dot are investigated. The device consists of two stacked graphene quantum dots separated by a…

Mesoscale and Nanoscale Physics · Physics 2016-03-01 Dominik Bischoff , Marius Eich , Oded Zilberberg , Clemens Rössler , Thomas Ihn , Klaus Ensslin

Charge noise is an important factor limiting qubit coherence and relaxation in solid-state devices. In bilayer graphene (BLG) quantum dots, recently established as a promising platform for spin- and valley-based qubits, both the origin and…

Distribution of charge induced by a gate voltage in a graphene strip is investigated. We calculate analytically the charge profile and demonstrate a strong(macroscopic) charge accumulation along the boundaries of a micrometers-wide strip.…

Mesoscale and Nanoscale Physics · Physics 2008-06-04 P. G. Silvestrov , K. B. Efetov

Measuring single-electron charge is one of the most fundamental quantum technologies. Charge sensing, which is an ingredient for the measurement of single spins or single photons, has been already developed for semiconductor gate-defined…

Mesoscale and Nanoscale Physics · Physics 2018-12-10 Haruki Kiyama , Alexander Korsch , Naomi Nagai , Yasushi Kanai , Kazuhiko Matsumoto , Kazuhiko Hirakawa , Akira Oiwa

We have incorporated an aluminum single electron transistor directly into the defining gate structure of a semiconductor quantum dot, permitting precise measurement of the charge in the dot. Voltage biasing a gate draws charge from a…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 D. Berman , N. B. Zhitenev , R. C. Ashoori , M. Shayegan

In situ tunable radio-frequency charge detection is used for the determination of the tunneling rates into and out of a graphene single quantum dot connected to only one lead. An analytical model for calculating these rates in the…

Mesoscale and Nanoscale Physics · Physics 2012-07-05 T. Müller , J. Güttinger , D. Bischoff , S. Hellmüller , K. Ensslin , T. Ihn

We demonstrate theoretically that quantum dots in bilayers of graphene can be realized. A position-dependent doping breaks the equivalence between the upper and lower layer and lifts the degeneracy of the positive and negative momentum…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 J. Milton Pereira , P. Vasilopoulos , F. M. Peeters

We report charge detection in degenerately phosphorus-doped silicon double quantum dots (DQD) electrically connected to an electron reservoir. The sensing device is a single electron transistor (SET) patterned in close proximity to the DQD.…

Mesoscale and Nanoscale Physics · Physics 2015-05-19 A. Rossi , T. Ferrus , G. J. Podd , D. A. Williams

We report on a double quantum dot which is formed in a width-modulated etched bilayer graphene nanoribbon. A number of lateral graphene gates enable us to tune the quantum dot energy levels and the tunneling barriers of the device over a…

Mesoscale and Nanoscale Physics · Physics 2013-03-20 Stefan Fringes , Christian Volk , Bernat Terrés , Jan Dauber , Stephan Engels , Stefan Trellenkamp , Christoph Stampfer

We combine electrostatic and magnetic confinement to define a quantum dot in bilayer graphene. The employed geometry couples $n$-doped reservoirs to a $p$-doped dot. At magnetic field values around $B = 2~$T, Coulomb blockade is observed.…

Mesoscale and Nanoscale Physics · Physics 2018-03-19 Hiske Overweg , Peter Rickhaus , Marius Eich , Yongjin Lee , Riccardo Pisoni , Kenji Watanabe , Takashi Taniguchi , Thomas Ihn , Klaus Ensslin

The detection of fractionally charged quasiparticles, which arise in the fractional quantum Hall regime, is of fundamental importance for probing their exotic quantum properties. While electronic interferometers have been central to probe…