A5011430095- Quantum and electron transport phenomena
- Semiconductor Quantum Structures and Devices
- Physics of Superconductivity and Magnetism
- Advancements in Semiconductor Devices and Circuit Design
- Quantum Information and Cryptography
- Magnetic properties of thin films
- Semiconductor materials and devices
- Topological Materials and Phenomena
- Strong Light-Matter Interactions
- Mechanical and Optical Resonators
- Graphene research and applications
- Cold Atom Physics and Bose-Einstein Condensates
- Electronic and Structural Properties of Oxides
- Quantum optics and atomic interactions
- Surface and Thin Film Phenomena
- Molecular Junctions and Nanostructures
- Quantum Computing Algorithms and Architecture
- Electron and X-Ray Spectroscopy Techniques
- Terahertz technology and applications
- GaN-based semiconductor devices and materials
- Advanced Thermodynamics and Statistical Mechanics
- Semiconductor Lasers and Optical Devices
- Photonic and Optical Devices
- Advanced Chemical Physics Studies
- Quantum many-body systems
ETH Zurich
2016-2025
Solid State Physics Laboratory
2011-2023
Bundesministerium für Land- und Forstwirtschaft, Umwelt und Wasserwirtschaft
2022
Board of the Swiss Federal Institutes of Technology
2012-2019
St. Pölten University of Applied Sciences
2019
Georgia State University
2016-2018
Delft University of Technology
2016-2018
QuTech
2016-2018
Bellingham Technical College
2018
Federal Ministry of Education, Science and Research
2017
Artificial cavity photon resonators with ultrastrong light-matter interactions are attracting interest both in semiconductor and superconducting systems, due to the possibility of manipulating quantum electrodynamic ground state controllable physical properties. We report here experiments showing coupling a terahertz metamaterial where cyclotron transition high mobility two-dimensional electron gas is coupled photonic modes an array electronic split-ring resonators. observe normalized ratio...
The control of the electronic properties materials via vacuum fields cavity electromagnetic resonators is one emerging frontiers condensed matter physics. We show here that enhancement field fluctuations in subwavelength split-ring dramatically affects arguably most paradigmatic quantum protectorates, namely Hall electron transport high-mobility 2D gases. observed breakdown topological protection integer effect interpreted terms a long-range cavity-mediated hopping where anti-resonant...
Independent readout of two single-spin qubits in quantum dots is achieved an all-electrical setup.
The ultrastrong light-matter interaction regime was investigated in metallic and superconducting complementary split ring resonators coupled to the cyclotron transition of two dimensional electron gases. sub-wavelength light confinement large optical dipole moment yield record high normalized coupling rates up $\frac{\Omega_R}{\omega_c}=$ 0.87. We observed a blue-shift both polaritons due diamagnetic term Hamiltonian.
The strong coupling limit of cavity quantum electrodynamics (QED) implies the capability a matter-like system to coherently transform an individual excitation into single photon within resonant structure. This not only enables essential processes required for information processing but also allows fundamental studies matter-light interaction. In this work we demonstrate between charge degree freedom in gate-detuned GaAs double dot (DQD) and frequency-tunable high impedance resonator realized...
Semiconductor quantum dots, where electrons or holes are isolated via electrostatic potentials generated by surface gates, promising building blocks for semiconductor-based technology. Here, we investigate double dot (DQD) charge qubits in GaAs, capacitively coupled to high-impedance SQUID array and Josephson junction resonators. We tune the strength of electric dipole interaction between qubit resonator in-situ using gates. characterize qubit-resonator coupling strength, decoherence,...
We explore the microwave radiation emitted from a biased double quantum dot due to inelastic tunneling of single charges. Radiation is detected over broad range detuning configurations between energy levels with pronounced maxima occurring in resonance capacitively coupled transmission line resonator. The power for forward and reverse resonant found be good agreement rate equation model, which considers hybridization individual charge states.
We demonstrate a coherent spin shuttle through GaAs/AlGaAs quadruple-quantum-dot array. Starting with two electrons in spin-singlet state the first dot, we one electron over to either second, third or fourth dot. observe that separated evolves periodically into $m=0$ spin-triplet and back before it dephases due nuclear noise. attribute time evolution differences local Zeeman splitting between respective dots. With help of numerical simulations, analyse discuss visibility singlet-triplet...
We measure weak quasiparticle tunneling across a constriction in the second Landau level. At $\nu$ = 7/3, 8/3 and 5/2, comparison of temperature DC bias dependence to theory allows extracting parameters that describe edges' excitations. 8/3, our results are well described by particle-hole conjugate Laughlin state, but not compatible with proposed non-Abelian For measurements good agreement previous experiments favor Abelian (3,3,1) or (1,1,3)-states. these filling factors, we further...
The realization of a coherent interface between distant charge or spin qubits in semiconductor quantum dots is an open challenge for information processing. Here, we demonstrate both resonant (real) and nonresonant (virtual) photon-mediated interactions double quantum-dot separated by several tens micrometers. We present clear spectroscopic evidence the collective enhancement coupling two resonator. With resonance with each other but detuned from resonator, observe exchange mediated virtual...
The interaction between electrons in arrays of electrostatically defined quantum dots is naturally described by a Fermi-Hubbard Hamiltonian. Moreover, the high degree tunability these systems makes them powerful platform to simulate different regimes Hubbard model. However, most dot array implementations have been limited one-dimensional linear arrays. In this letter, we present square lattice unit cell 2 × an AlGaAs/GaAs heterostructure using double-layer gate technique. We probe properties...
Semiconductor quantum dot arrays defined electrostatically in a 2D electron gas provide scalable platform for information processing and simulations. For the operation of arrays, appropriate voltages need to be applied gate electrodes that define potential landscape. Tuning has proven time-consuming task, because initial electrostatic disorder capacitive cross-talk effects. Here, we report on automated tuning inter-dot tunnel coupling gate-defined semiconductor double dots. The automation is...
Developing fast and accurate control readout techniques is an important challenge in quantum information processing with semiconductor qubits. Here, we study the dynamics coherence properties of a GaAs/AlGaAs double dot (DQD) charge qubit strongly coupled to high-impedance SQUID array resonator. We drive transitions synthesized microwave pulses perform through state dependent frequency shift imparted by on dispersively Rabi oscillation, Ramsey fringe, energy relaxation Hahn-echo measurements...
While quantum dots are at the forefront of device technology, tuning multi-dot systems requires a lengthy experimental process as multiple parameters need to be accurately controlled. This becomes increasingly time-consuming and difficult perform manually devices become more complex number grows. In this work, we present crucial step towards automated dot qubits. We introduce an algorithm driven by machine learning that uses small coarse-grained measurements its input tunes system into...
We have realized a hybrid solid-state quantum device in which single-electron semiconductor double dot is dipole coupled to superconducting microwave frequency transmission line resonator. The dipolar interaction between the two entities manifests itself via dispersive and dissipative effects observed as shifts linewidth broadenings of photonic mode respectively. A Jaynes-Cummings Hamiltonian master equation calculation used model combined system response allows for determining both...
We report a magnetotransport study of an ultra-high mobility ($\bar{\mu}\approx 25\times 10^6$\,cm$^2$\,V$^{-1}$\,s$^{-1}$) $n$-type GaAs quantum well up to 33 T. A strong linear magnetoresistance (LMR) the order 10$^5$ % is observed in wide temperature range between 0.3 K and 60 K. The simplicity our material system with single sub-band occupation free electron dispersion rules out most complicated mechanisms that could give rise LMR. At low temperature, oscillations are superimposed onto...
Spin qubits and superconducting are among the promising candidates for realizing a solid state quantum computer. For implementation of hybrid architecture which can profit from advantages either approach, coherent link is necessary that integrates controllably couples both qubit types on same chip over distance several orders magnitude longer than physical size spin qubit. We realize such with frequency-tunable high impedance SQUID array resonator. The resonant exchange hosted in GaAs triple...
Abstract Many properties of solids result from the fact that in a periodic crystal structure, electronic wave functions are delocalized over many lattice sites. Electrons should become increasingly localized when strong electric field is applied. So far, this Wannier–Stark regime has been reached only artificial superlattices. Here we show extremely transient bias few-femtosecond period phase-stable mid-infrared pulses may localize electrons even bulk semiconductor like GaAs. The complicated...