We introduce an always-on, exchange-only qubit made up of three localized semiconductor spins that offers a true “sweet spot” to fluctuations of the quantum dot energy levels.

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## Always-on Exchange-ONly (AEON) spin-based qubits

July 20th, 2016 | by admin | published in Featured, Quantum Computing, Research

## Semiconductor-inspired superconducting quantum computing

March 19th, 2016 | by admin | published in Featured, Quantum Computing, Research

Superconducting circuits offer tremendous design flexibility in the quantum regime culminating most recently in the demonstration of few qubit systems supposedly approaching the threshold for fault-tolerant quantum information processing. Competition in the solid-state comes from semiconductor qubits, where nature has bestowed some very useful properties which can be utilized for spin qubit based quantum computing. […]

## Nature Communications: Semiconductor-inspired design principles for superconducting quantum computing

March 16th, 2016 | by admin | published in News, Papers, Quantum Computing

Superconducting circuits offer tremendous design flexibility in the quantum regime culminating most recently in the demonstration of few qubit systems supposedly approaching the threshold for fault-tolerant quantum information processing. Competition in the solid-state comes from semiconductor qubits, where nature has bestowed some very useful properties which can be utilized for spin qubit-based quantum computing. Here […]

## Preprint: Charge-noise-insensitive gate operations for always-on, exchange-only qubits

January 31st, 2016 | by admin | published in News, Preprints, Quantum Computing

We introduce an always-on, exchange-only qubit made up of three localized semiconductor spins that offers a true “sweet spot” to fluctuations of the quantum dot energy levels. Both single- and two-qubit gate operations can be performed using only exchange pulses while maintaining this sweet spot. We show how to interconvert this qubit to other three-spin […]

## Paper: Spin-orbit coupling and operation of multi-valley spin qubits

November 5th, 2015 | by admin | published in News, Papers, Quantum Computing

Spin qubits composed of either one or three electrons are realized in a quantum dot formed at a Si/SiO_2-interface in isotopically enriched silicon. Using pulsed electron spin resonance, we perform coherent control of both types of qubits, addressing them via an electric field dependent g-factor. We perform randomized benchmarking and find that both qubits can […]

## How to make superconducting circuits out of a semiconductor

July 4th, 2014 | by admin | published in Featured, Quantum Computing, Research

Superconducting circuits are exceptionally flexible, enabling many different devices from sensors to quantum computers. Separately, epitaxial semiconductor devices such as spin qubits in silicon offer more limited device variation but extraordinary quantum properties for a solid-state system. It might be possible to merge the two approaches, making single-crystal superconducting devices out of a semiconductor by […]

## On-chip cavity quantum phonodynamics and acceptor qubits in silicon

September 8th, 2013 | by admin | published in All, Featured, Highlights, Nanotechnology, Phonitons, Quantum Computing, Research

## Phys. Rev. B: On-chip cavity quantum phonodynamics with an acceptor qubit in silicon

August 30th, 2013 | by admin | published in All, Nanotechnology, News, Papers, Phonitons, Quantum Computing

We describe a chip-based, solid-state analog of cavity-QED utilizing acoustic phonons instead of photons. We show how long-lived and tunable acceptor impurity states in silicon nanomechanical cavities can play the role of a matter nonlinearity for coherent phonons just as, e.g., the Josephson qubit plays in circuit QED. Both strong coupling (number of Rabi oscillations ≲100) and strong dispersive coupling (0.1–2 MHz) regimes can be reached in cavities in the 1–20-GHz range, enabling the control of single phonons, phonon-phonon interactions, dispersive phonon readout of the acceptor qubit, and compatibility with other optomechanical components such as phonon-photon translators. We predict explicit experimental signatures of the acceptor-cavity system.

## Preprint: Observation of Autler-Townes effect in a dispersively dressed Jaynes-Cummings system

August 9th, 2013 | by admin | published in All, News, Preprints, Quantum Computing

Two-tone spectroscopy of a superconducting transmon qubit in a cavity. We find evidence of strongly-coupled atomic physics in these man-made systems.

Superconducting qubits and circuits are a promising technology for a variety of applications, from exploration of physics to quantum information processing or particle detectors.

## Preprint: Relaxation of excited spin, orbital, and valley qubit states in single electron silicon quantum dots

January 25th, 2013 | by admin | published in All, Blog, Preprints, Quantum Computing

We review and expand on previous work that treats relaxation physics of low-lying excited states in ideal, single electron, silicon quantum dots in the context of quantum computing. These states are of three types: orbital, valley, and spin. The relaxation times depend sensitively on system parameters such as the dot size and the external magnetic […]