758 citations · 1k across the 18 of their papers we have counts for
18 papers
Quantum communication networks with defects in silicon carbide
Philipp Sohr, Philipp Koller, Sebastian Ecker +23
Quantum communication promises unprecedented capabilities enabled by the transmission of quantum states of light. However, current implementations face severe distance limitations…
Charge dynamics in the 2D/3D semiconductor heterostructure WSe/GaAs
Rafael R. Rojas-Lopez, Freddie Hendriks, Caspar H. van der Wal +2
Understanding the relaxation and recombination processes of excited states in two-dimensional (2D)/three-dimensional (3D) semiconductor heterojunctions is essential for developing…
Magnetic field control of light-induced spin accumulation in monolayer MoSe
Rafael R. Rojas-Lopez, Freddie Hendriks, Caspar H. van der Wal +2
Semiconductor transition metal dichalcogenides (TMDs) have equivalent dynamics for their two spin/valley species. This arises from their energy-degenerated spin states, connected v…
Vanadium in Silicon Carbide: Telecom-ready spin centres with long relaxation lifetimes and hyperfine-resolved optical transitions
T. Astner, P. Koller, C. M. Gilardoni +6
Vanadium in silicon carbide (SiC) is emerging as an important candidate system for quantum technology due to its optical transitions in the telecom wavelength range. However, sever…
Observation of bright and dark exciton transitions in monolayer MoSe2 by photocurrent spectroscopy
Jorge Quereda, Talieh S. Ghiasi, Feitze A. van Zwol +2
We investigate the excitonic transitions in single- and few-layer MoSe2 phototransistors by photocurrent spectroscopy. The measured spectral profiles show a well-defined peak at th…
Stabilizing nuclear spins around semiconductor electrons via the interplay of optical coherent population trapping and dynamic nuclear polarization
A. R. Onur, J. P. de Jong, D. O'Shea +3
We experimentally demonstrate how coherent population trapping (CPT) for donor-bound electron spins in GaAs results in autonomous feedback that prepares stabilized states for the s…
All-optical coherent population trapping with defect spin ensembles in silicon carbide
Olger V. Zwier, Danny O'Shea, Alexander R. Onur +1
Divacancy defects in silicon carbide have long-lived electronic spin states and sharp optical transitions, with properties that are similar to the nitrogen-vacancy defect in diamon…
Two-laser dynamic nuclear polarization with semiconductor electrons: feedback, suppressed fluctuations, and bistability near two-photon resonance
Alexander R. Onur, Caspar H. van der Wal
We present how optical coherent population trapping (CPT) of the spin of localized semiconductor electrons stabilizes the surrounding nuclear spin bath via the hyperfine interactio…
Analysis of optical differential transmission signals from co-propagating fields in a lambda system medium
J. P. de Jong, A. R. Onur, D. Reuter +2
We analyze theoretically and experimentally how nonlinear differential-transmission spectroscopy of a lambda-system medium can provide quantitative understanding of the optical dip…
Robust recipe for low-resistance ohmic contacts to a two-dimensional electron gas in a GaAs/AlGaAs heterostructure
M. J. Iqbal, D. Reuter, A. D. Wieck +1
The study of electron transport in low-dimensional systems is of importance, not only from a fundamental point of view, but also for future electronic and spintronic devices. In th…
Odd and even Kondo effects from emergent localisation in quantum point contacts
M. J. Iqbal, Roi Levy, E. J. Koop +8
A quantum point contact (QPC) is a very basic nano-electronic device: a short and narrow transport channel between two electron reservoirs. In clean channels electron transport is…
Polarization-preserving confocal microscope for optical experiments in a dilution refrigerator with high magnetic field
Maksym Sladkov, M. P. Bakker, A. U. Chaubal +3
We present the design and operation of a fiber-based cryogenic confocal microscope. It is designed as a compact cold-finger that fits inside the bore of a superconducting magnet, a…
Electromagnetically Induced Transparency with an Ensemble of Donor-Bound Electron Spins in a Semiconductor
Maksym Sladkov, A. U. Chaubal, M. P. Bakker +4
We present measurements of electromagnetically induced transparency with an ensemble of donor- bound electrons in low-doped n-GaAs. We used optical transitions from the Zeeman-spli…
Optical probing of spin dynamics of two-dimensional and bulk electrons in a GaAs/AlGaAs heterojunction system
P. J. Rizo, A. Pugzlys, A. Slachter +5
We present time-resolved Kerr rotation measurements of electron spin dynamics in a GaAs/AlGaAs heterojunction system that contains a high-mobility two-dimensional electron gas (2DE…
Suppressed spin dephasing for 2D and bulk electrons in GaAs wires due to engineered cancellation of spin-orbit interaction terms
S. Z. Denega, T. Last, J. Liu +7
We report a study of suppressed spin dephasing for quasi-one-dimensional electron ensembles in wires etched into a GaAs/AlGaAs heterojunction system. Time-resolved Kerr-rotation me…
The annealing mechanism of AuGe/Ni/Au ohmic contacts to a two-dimensional electron gas in GaAs/AlGaAs heterostructures
E. J. Koop, M. J. Iqbal, F. Limbach +6
Ohmic contacts to a two-dimensional electron gas (2DEG) in GaAs/AlGaAs heterostructures are often realized by annealing of AuGe/Ni/Au that is deposited on its surface. We studied h…
Persistence of the 0.7 anomaly of quantum point contacts in high magnetic fields
E. J. Koop, A. I. Lerescu, J. Liu +4
The spin degeneracy of the lowest subband that carries one-dimensional electron transport in quantum point contacts appears to be spontaneously lifted in zero magnetic field due to…
A Superconducting Persistent Current Qubit
T. P. Orlando, J. E. Mooji, Lin Tian +4
We present the design of a superconducting qubit that has circulating currents of opposite sign as its two states. The circuit consists of three nano-scale aluminum Josephson junct…