Publications (27)
Single-photon-emitting diodes: a review
A. J. Bennett, P. Atkinson, P. See +8
Compact and reliable sources of non-classical light could find many applications in emerging technologies such as quantum cryptography, quantum imaging and also in fundamental test…
Cryogenic on-chip multiplexer for the study of quantum transport in 256 split-gate devices
H. Al-Taie, L. W. Smith, B. Xu +7
We present a multiplexing scheme for the measurement of large numbers of mesoscopic devices in cryogenic systems. The multiplexer is used to contact an array of 256 split gates on…
Coulomb sensing of single ballistic electrons
J. D. Fletcher, W. Park, P. See +6
While ballistic electrons are a key tool for applications in sensing and flying qubits, sub-nanosecond propagation times and complicated interactions make control of ballistic sing…
Ultrafast Voltage Sampling using Single-Electron Wavepackets
N. Johnson, J. D. Fletcher, D. A. Humphreys +8
We demonstrate an ultrafast voltage sampling technique using a stream of electron wavepackets. Electrons are emitted from a single-electron pump and travel through electron wavegui…
LO-phonon emission rate of hot electrons from an on-demand single-electron source in a GaAs/AlGaAs heterostructure
N. Johnson, C. Emary, S. Ryu +10
Using a recently-developed time-of-flight measurement technique with 1 ps time resolution and electron-energy spectroscopy, we developed a method to measure the longitudinal-optica…
Time-resolved Coulomb collision of single electrons
J. D. Fletcher, W. Park, S. Ryu +7
Precise control over interactions between ballistic electrons will enable us to exploit Coulomb interactions in novel ways, to develop high-speed sensing, to reach a non-linear reg…
Statistical study and parallelisation of multiplexed single-electron sources
S. Norimoto, P. See, N. Schoinas +7
Increasing electric current from a single-electron source is a main challenge in an effort to establish the standard of the ampere defined by the fixed value of the elementary char…
Dependence of the 0.7 anomaly on the curvature of the potential barrier in quantum wires
L. W. Smith, H. Al-Taie, A. A. J. Lesage +9
Ninety eight one-dimensional channels defined using split gates fabricated on a GaAs/AlGaAs heterostructure are measured during one cooldown at 1.4 K. The devices are arranged in a…
Anomalous critical fields in quantum critical superconductors
C. Putzke, P. Walmsley, J. D. Fletcher +12
Fluctuations around an antiferromagnetic quantum critical point (QCP) are believed to lead to unconventional superconductivity and in some cases to high-temperature superconductivi…
Quantum key distribution using a triggered quantum dot source emitting near 1.3 microns
P. M. Intallura, M. B. Ward, O. Z. Karimov +5
We report the distribution of a cryptographic key, secure from photon number splitting attacks, over 35 km of optical fiber using single photons from an InAs quantum dot emitting ~…
A low-temperature device architecture for the statistical study of electrical characteristics of 256 quantum devices
H. Al-Taie, L. W. Smith, B. Xu +7
Research in the field of low-temperature electronics is limited by the small number of electrical contacts available on cryogenic set ups. This not only restricts the number of dev…
Stabilization of single-electron pumps by high magnetic fields
J. D. Fletcher, M. Kataoka, S. P. Giblin +8
We study the effect of perpendicular magnetic fields on a single-electron system with a strongly time-dependent electrostatic potential. Continuous improvements to the current quan…
Rectification in mesoscopic AC-gated semiconductor devices
S. P. Giblin, M. Kataoka, J. D. Fletcher +6
We measure the rectified dc currents resulting when a 3-terminal semiconductor device with gate-dependent conductance is driven with an ac gate voltage. The rectified currents exhi…
Formation of a lateral p-n junction light-emitting diode on an n-type high-mobility GaAs/AlGaAs heterostructure
C. P. Dobney, A. Nasir, P. See +5
We have fabricated a device which includes two lateral p-n junctions on an n-type GaAs/AlGaAs heterostructure. A section of the n-type material has been converted…
A surface-patterned chip as a strong source of ultra-cold atoms for quantum technologies
C. C. Nshii, M. Vangeleyn, J. P. Cotter +7
Laser cooled atoms are central to modern precision measurements. They are also increasingly important as an enabling technology for experimental cavity quantum electrodynamics, qua…
Towards a quantum representation of the ampere using single electron pumps
S. P. Giblin, M. Kataoka, J. D. Fletcher +6
Electron pumps generate a macroscopic electric current by controlled manipulation of single electrons. Despite intensive research towards a quantum current standard over the last 2…
Statistical study of conductance properties in one-dimensional quantum wires focussing on the 0.7 anomaly
L. W. Smith, H. Al-Taie, F. Sfigakis +9
The properties of conductance in one-dimensional (1D) quantum wires are statistically investigated using an array of 256 lithographically-identical split gates, fabricated on a GaA…
Fast characterization of multiplexed single-electron pumps with machine learning
N. Schoinas, Y. Rath, S. Norimoto +8
We present an efficient machine learning based automated framework for the fast tuning of single-electron pump devices into current quantization regimes. It uses a sparse measureme…
Photon emission by hot electron injection across a lateral \textit{pn} junction
S. Norimoto, R. Saxena, P. See +5
We demonstrate a method to generate photons by injecting hot electrons into a {\it pn} junction within a \ce{GaAs/AlGaAs} heterostructure. Hot electrons are generated by biasing ac…
Error detection in a tunable-barrier electron pump
S. P. Giblin, P. See, J. D. Fletcher +5
We measure the average number of electrons loaded into an electrostatically-defined quantum dot (QD) operated as a tunable-barrier electron pump, using a point-contact (PC) charge…
Time-of-Flight Measurements of Single-Electron Wave Packets in Quantum-Hall Edge States
M. Kataoka, N. Johnson, C. Emary +7
We report time-of-flight measurements on electrons travelling in quantum-Hall edge states. Hot-electron wave packets are emitted one per cycle into edge states formed along a deple…
Measurement and control of electron wave packets from a single-electron source
J. Waldie, P. See, V. Kashcheyevs +6
We report an experimental technique to measure and manipulate the arrival-time and energy distributions of electrons emitted from a semiconductor electron pump, operated as both a…
High-resolution error detection in the capture process of a single-electron pump
S. P. Giblin, P. See, A. Petrie +6
The dynamic capture of electrons in a semiconductor quantum dot (QD) by raising a potential barrier is a crucial stage in metrological quantized charge pumping. In this work, we us…
Clock-controlled emission of single-electron wavepackets in a solid-state circuit
J. D. Fletcher, M. Kataoka, H. Howe +8
We demonstrate the transmission of single electron wavepackets from a clock-controlled source through an empty high-energy edge channel. The quantum dot source is loaded with singl…
The effect of split gate size on the electrostatic potential and 0.7 anomaly within one-dimensional quantum wires on a modulation doped GaAs/AlGaAs heterostructure
L. W. Smith, H. Al-Taie, A. A. J. Lesage +9
We study 95 split gates of different size on a single chip using a multiplexing technique. Each split gate defines a one-dimensional channel on a modulation-doped GaAs/AlGaAs heter…
Continuous-Variable Tomography of Solitary Electrons
J. D. Fletcher, N. Johnson, E. Locane +7
A method for characterising the wave-function of freely-propagating particles would provide a useful tool for developing quantum-information technologies with single electronic exc…
Magnetic-field-induced reduction of the exciton polarization splitting in InAs quantum dots
R. M. Stevenson, R. J. Young, P. See +6
By the application of an in-plane magnetic field, we demonstrate control of the fine structure polarisation splitting of the exciton emission lines in individual InAs quantum dots.…