A5076519965- Quantum Information and Cryptography
- Quantum and electron transport phenomena
- Mechanical and Optical Resonators
- Quantum Computing Algorithms and Architecture
- Physics of Superconductivity and Magnetism
- Photonic and Optical Devices
- Quantum Mechanics and Applications
- Advanced MEMS and NEMS Technologies
- Cold Atom Physics and Bose-Einstein Condensates
- Superconducting and THz Device Technology
- Acoustic Wave Resonator Technologies
- Force Microscopy Techniques and Applications
- Advancements in Semiconductor Devices and Circuit Design
- Particle accelerators and beam dynamics
- Quantum optics and atomic interactions
- Neural Networks and Reservoir Computing
- Microfluidic and Bio-sensing Technologies
- Gyrotron and Vacuum Electronics Research
- Microfluidic and Capillary Electrophoresis Applications
- Pain Management and Treatment
- Surface and Thin Film Phenomena
- Molecular Junctions and Nanostructures
- Advanced Thermodynamics and Statistical Mechanics
- Advanced Fiber Laser Technologies
- Advanced Frequency and Time Standards
Argonne National Laboratory
2019-2025
University of Chicago
2015-2024
Medtronic (United States)
2022-2024
The University of Queensland
2020
University of California, Santa Barbara
2007-2019
Royal Society Te Apārangi
2017
California NanoSystems Institute
2006-2014
University of California, Berkeley
1987-2013
Hebrew University of Jerusalem
2008
University of California, Riverside
2006
This article provides an introduction to surface code quantum computing. We first estimate the size and speed of a computer. then introduce concept stabilizer, using two qubits, extend this stabilizers acting on two-dimensional array physical which we implement code. next describe how logical qubits are formed in give numerical estimates their fault-tolerance. outline physically moved array, qubit braid transformations constructed, between is equivalent controlled-NOT. single-qubit Hadamard,...
We demonstrate a planar, tunable superconducting qubit with energy relaxation times up to $44\text{ }\text{ }\ensuremath{\mu}\mathrm{s}$. This is achieved by using geometry designed both minimize radiative loss and reduce coupling materials-related defects. At these levels of coherence, we find fine structure in the lifetime as function frequency, indicating presence sparse population incoherent, weakly coupled two-level elucidate this defect physics experimentally varying model analysis....
We report on a method to fabricate nanometer scale mechanical structures from bulk, single-crystal Si substrates. A technique developed previously required more complex fabrication methods and an undercut step using wet chemical processing. Our does not require low pressure vapor deposition of intermediate masking layers, the final in processing uses dry etch technique, avoiding difficulties encountered surface tension effects when mechanically delicate or large aspect ratio structures....
Demonstration of quantum entanglement, a key resource in computation arising from nonclassical correlation states, requires complete measurement all states varying bases. By using simultaneous and state tomography, we demonstrated entanglement between two solid-state qubits. Single qubit operations capacitive coupling super-conducting phase qubits were used to generate Bell-type state. Full two-qubit tomography yielded density matrix showing an entangled with fidelity up 87%. Our results...
Nanomechanical resonators can be fabricated to achieve high natural resonance frequencies, approaching 1 GHz, with quality factors in excess of 104. These are candidates for use as highly selective rf filters and precision on-chip clocks. Some fundamental some nonfundamental noise processes will present limits the performance such resonators. include thermomechanical noise, Nyquist–Johnson adsorption–desorption noise; other important sources those due thermal fluctuations defect...
Progress in superconducting qubit experiments with greater numbers of qubits or advanced techniques such as feedback requires faster and more accurate state measurement. We have designed a multiplexed measurement system bandpass filter that allows fast without increasing environmental damping the qubits. use this to demonstrate simultaneous four on single integrated circuit, fastest which can be measured 99.8% accuracy 140ns. This speed is suitable for multi-qubit including surface code...
Experiments to investigate the quantum behavior of a macroscopic degree freedom, namely phase difference across Josephson tunnel junction, are described. The experiments involve measurements escape rate junction from its zero voltage state. Low temperature for junctions that either nearly undamped or moderately damped agree very closely with predictions tunneling, no adjustable parameters. Microwave spectroscopy reveals quantized energy levels in potential well excellent agreement...
Abstract Today, surface acoustic waves (SAWs) and bulk are already two of the very few phononic technologies industrial relevance can been found in a myriad devices employing these nanoscale earthquakes on chip. Acoustic radio frequency filters, for instance, integral parts wireless devices. SAWs particular find applications life sciences microfluidics sensing mixing tiny amounts liquids. In addition to this continuously growing number applications, ideally suited probe control elementary...
The von Neumann architecture for a classical computer comprises central processing unit and memory holding instructions data. We demonstrate quantum that exchanges data with random-access integrated on chip, stored computer. test our machine by executing codes involve seven elements: Two superconducting qubits coupled through bus, two memories, zeroing registers. vital algorithms computing are demonstrated, the Fourier transform, 66% process fidelity, three-qubit Toffoli-class OR phase gate,...
In quantum information processing, qudits (d-level systems) are an extension of qubits that could speed up certain computing tasks. We demonstrate the operation a superconducting phase qudit with number levels d to = 5 and show how manipulate measure state, including simultaneous control multiple transitions. used emulate dynamics single spins principal s 1/2, 1, 3/2, allowing measurement Berry's even parity integer (and odd half-integer spins) under 2pi-rotation. This two-level qubit...
We describe the fabrication and measurement of microwave coplanar waveguide resonators with internal quality factors above 10 million at high powers over 1 low powers, best power results approaching 2 million, corresponding to ~1 photon in resonator. These are achieved by controllably producing very smooth clean interfaces between resonators' aluminum metallization underlying single crystal sapphire substrate. Additionally, we a method for analyzing resonator response, which can directly...
We find that stray infrared light from the 4 K stage in a cryostat can cause significant loss superconducting resonators and qubits. For devices shielded only metal box, we measured with quality factors Q = 10^5 qubits energy relaxation times T_1=120 ns, consistent light-induced quasiparticle density of 170-230 \mu m^{-3}. By adding second black shield at sample temperature, found about an order magnitude improvement performance no sensitivity to radiation. also tested various shielding...