A5001323831- Quantum and electron transport phenomena
- Advancements in Semiconductor Devices and Circuit Design
- Semiconductor Quantum Structures and Devices
- Quantum Computing Algorithms and Architecture
- Semiconductor materials and devices
- Quantum Information and Cryptography
- Physics of Superconductivity and Magnetism
- Graphene research and applications
- Surface and Thin Film Phenomena
- Mechanical and Optical Resonators
- Photonic and Optical Devices
- Quantum, superfluid, helium dynamics
- Magnetic properties of thin films
- Topological Materials and Phenomena
- Calibration and Measurement Techniques
- Integrated Circuits and Semiconductor Failure Analysis
- Cold Atom Physics and Bose-Einstein Condensates
- Advanced Data Storage Technologies
- Distributed and Parallel Computing Systems
- Quantum-Dot Cellular Automata
- Magneto-Optical Properties and Applications
- Advanced Thermodynamics and Statistical Mechanics
- Atmospheric Ozone and Climate
- Nuclear Physics and Applications
- Silicon and Solar Cell Technologies
QuTech
2016-2024
Netherlands Organisation for Applied Scientific Research
2020-2024
Delft University of Technology
2016-2022
Purdue University West Lafayette
2010-2018
High-fidelity control of quantum bits is paramount for the reliable execution algorithms and achieving fault-tolerance, ability to correct errors faster than they occur. The central requirement fault-tolerance expressed in terms an error threshold. Whereas actual threshold depends on many details, a common target ~1% well-known surface code. Reaching two-qubit gate fidelities above 99% has been long-standing major goal semiconductor spin qubits. These qubits are well positioned scaling as...
We report the strong coupling of a single electron spin and microwave photon. The is trapped in silicon double quantum dot photon stored an on-chip high-impedance superconducting resonator. electric field component cavity couples directly to charge dipole dot, indirectly spin, through local magnetic gradient from nearby micromagnet. This result opens way realization large networks based qubit registers, removing major roadblock scalable computing with qubits.
Full-scale quantum computers require the integration of millions bits. The promise leveraging industrial semiconductor manufacturing to meet this requirement has fueled pursuit computing in silicon dots. However, date, their fabrication relied on electron-beam lithography and, with few exceptions, academic style lift-off processes. Although these techniques offer process flexibility, they suffer from low yield and poor uniformity. An important question is whether processing conditions...
We present superconducting microwave-frequency resonators based on NbTiN nanowires. The small cross section of the nanowires minimizes vortex generation, making resilient to magnetic fields. Measured intrinsic quality factors exceed $2\times 10^5$ in a $6$ T in-plane field, and $3\times 10^4$ $350$ mT perpendicular field. Due their high characteristic impedance, these are expected develop zero-point voltage fluctuations one order magnitude larger than standard coplanar waveguide resonators....
Building a large-scale quantum computer requires the co-optimization of both bits (qubits) and their control electronics. By operating CMOS circuits at cryogenic temperatures (cryo-CMOS), hence in close proximity to solid-state qubits, compact quantum-computing system can be achieved, thus promising scalability large number qubits required practical application. This work presents cryo-CMOS microwave signal generator for frequency-multiplexed 4 × 32 (32 per RF output). A digitally intensive...
Quantum computers (QC), comprising qubits and a classical controller, can provide exponential speed-up in solving certain problems. Among solid-state qubits, transmons spin-qubits are the most promising, operating ≪ 1K. A qubit be implemented physical system with two distinct energy levels representing |0) |1) states, e.g. up down spin states of an electron. The manipulated microwave pulses, whose frequency f matches level spacing E = hf (Fig. 19.1.1). For transmons, ~ 6GHz, for 20GHz,...
Abstract Electron spins in Si/SiGe quantum wells suffer from nearly degenerate conduction band valleys, which compete with the spin degree of freedom formation qubits. Despite attempts to enhance valley energy splitting deterministically, by engineering a sharp interface, fluctuations remain serious problem for qubit uniformity, needed scale up large processors. Here, we elucidate and statistically predict holistic integration 3D atomic-level properties, theory transport. We find that...
Abstract The electrical characterisation of classical and quantum devices is a critical step in the development cycle heterogeneous material stacks for semiconductor spin qubits. In case silicon, properties such as disorder energy separation conduction band valleys are commonly investigated individually upon modifications selected parameters stack. However, this reductionist approach fails to consider interdependence between different structural electronic at danger optimising one metric...
Frequency multiplexing of operations is an attractive strategy to control multiple qubits simultaneously in a spin-based quantum processor with relatively few lines. However, high-fidelity operation demands good spectral addressability and noncontextual spin dynamics. The authors explore unexpected crosstalk mechanism, which the Rabi frequency one changes markedly depending on simultaneous another. They also connect this behavior another surprising feature: nonlinear scaling resonant driving...
We fabricated a He-3 immersion cell for transport measurements of semiconductor nanostructures at ultra low temperatures and in strong magnetic fields. have new scheme field-independent thermometry based on quartz tuning fork Helium-3 viscometry which monitors the local temperature sample's environment real time. The operation measurement circuitry viscometer is described detail. provide evidence that two-dimensional electron gas confined to GaAs quantum well follows down 4mK.
The region of filling factors $1/3<\ensuremath{\nu}<2/5$ is predicted to support new types fractional quantum Hall states with topological order different from that the Laughlin-Jain or Moore-Read states. Incompressibility a necessary condition for formation such novel We find at 6.9 mK incompressibility develops only $\ensuremath{\nu}=4/11$ and $5/13$, while $\ensuremath{\nu}=6/17$ $3/8$ remain compressible. Our observations $5/13$ are first steps towards understanding emergent in these
Circuit quantum electrodynamics (QED) employs superconducting microwave resonators as buses. In circuit QED with semiconductor quantum-dot-based qubits, increasing the resonator impedance is desirable it enhances coupling to typically small charge dipole moment of these qubits. However, gate electrodes necessary form dots in vicinity a inadvertently lead parasitic port through which photons can leak, thereby reducing quality factor resonator. This particularly case for high-impedance...
We report a reliable method to estimate the disorder broadening parameter from scaling of gaps even and major odd denominator fractional quantum Hall states second Landau level. apply this technique several samples vastly different densities grown in molecular beam epitaxy chambers. Excellent agreement is found between estimated intrinsic numerically obtained energy for $\ensuremath{\nu}=5/2$ state. Furthermore, we quantify dependence gap at on Landau-level mixing.
Quantum computing's value proposition of an exponential speedup in computing power for certain applications has propelled a vast array research across the globe. While several different physical implementations device level qubits are being investigated, semiconductor spin have many similarities to scaled transistors. In this article, we discuss device/integration full 300mm based qubit devices. This includes development (i) <sup xmlns:mml="http://www.w3.org/1998/Math/MathML"...
Radio-frequency (rf) reflectometry offers a fast and sensitive method for charge sensing spin readout in gated quantum dots. We focus this work on the implementation of rf accumulation-mode gate-defined dots, where large parasitic capacitance poses challenge. describe test two methods mitigating effect capacitance, one by on-chip modifications second off-chip changes. demonstrate that enable high-performance $\mathrm{Si}$/${\mathrm{Si}}_{x}$${\mathrm{Ge}}_{1\ensuremath{-}x}$ achieving...
The mission of QuTech is to bring quantum technology industry and society by translating fundamental scientific research into applied research. To this end we are developing Quantum Inspire (QI), a full-stack computer prototype for future co-development collaborative R&D in computing. A prerelease system already offering the public cloud-based access technologies such as programmable simulator (with up 31 qubits) tutorials user background knowledge on information science...
We have studied the $\ensuremath{\nu}=5/2$ fractional quantum Hall state in a density-tunable sample at extremely low electron densities. For densities accessed our experiment, Landau level mixing parameter $\ensuremath{\kappa}$ spans $2.52<\ensuremath{\kappa}<2.82$ range. In vicinity of $5.8\ifmmode\times\else\texttimes\fi{}{10}^{10}\phantom{\rule{4pt}{0ex}}{\mathrm{cm}}^{\ensuremath{-}2}$ or $\ensuremath{\kappa}=2.6$ an anomalously large change density dependence energy gap is observed....
In spite of its ubiquity in strongly correlated systems, the competition paired and nematic ground states remains poorly understood. Recently such a was reported two-dimensional electron gas at filling factor $\nu=5/2$. At this pressure-induced quantum phase transition observed from fractional Hall state to nematic. Here we show that pressure induced paired-to-nematic also develops $\nu=7/2$, demonstrating therefore both spin branches second orbital Landau level. However, find is not only...
Under hydrostatic pressure, the ground state of a two-dimensional electron gas at $\nu=5/2$ changes from fractional quantum Hall to stripe phase. By measuring energy gap and onset temperature phase we mapped out diagram these competing phases in pressure-temperature plane. Our data highlight dichotomy two descriptions half-filled Landau level near critical point: one based on electrons another composite fermions.