Martinis Group

Josephson Junction Quantum Computing at UCSB

UCSB to partner with Google to build a quantum computer

Google

Quantum AI Google+ page, Google Research Blog

Wired, Wall Street Journal, IEEE Spectrum, MIT Tech Report

Superconducting circuits at the surface code threshold for fault tolerance

5 Xmon transmons at surface code threshold

The superconducting quantum circuit with five Xmon qubits (cross-shaped devices) placed in a linear array. The quantum device shows logic gates with fidelities at the surface code threshold for fault tolerance. (Photo credit: Erik Lucero.) This Nature article has been featured in a press release, Christian Science Monitor, IEEE Spectrum, International Business Times, Condensed Matter Journal Club, Photonics Spectra, EE Journal, Science News, and Techfragments.

2014 NSF Fellows

Congratulations to Zijun "Jimmy" Chen and Chris Quintana on being awarded NSF Graduate Research Fellowships for 2014.

Nature Physics Cover Page

Photon shell game with ReZQu architecture

This illustration by Dario Mariantoni and our own Erik Lucero and Matteo Mariantoni graced the April 2011 cover of Nature Physics along with an article on shuffling photons between resonators in the ReZQu architecture.

Superconducting Qubits featured by the BBC

ReZQu architecture

This photo by Erik Lucero illustrates our lab's ReZQu qubit architecture, the focus of a BBC article.

AAAS Science "Breakthrough of the year"

Alumnus Dr. Aaron O'Connell was recognized by the AAAS journal Science for 2010's scientific Breakthrough of the year for his Nature article, "Quantum ground state and single-phonon control of a mechanical resonator".

Mechanical resonator coupled to a Qubit

Pictured above is the actual device used in the experiment. The mechanical resonator, which was placed in a superposition, is situated in the bottom left of the chip. The smaller white rectangle is the coupling capacitor between the mechanical resonator and the qubit. Photo by Erik Lucero.

Superconducting Qubits featured in the New York Times

4 qubits symmetrically coupled

This photo by our own Erik Lucero is featured in the New York Times article highlighting our recent work on generating three-qubit entanglement (Neeley et al., Nature 467, 570-573 (2010). See publications.) along with work from the Schoelkopf group at Yale.

Superconducting Qubits featured in Physics Today

Physics Today cover Quantum Control cover

This photo by our own Erik Lucero graced the cover of the July 2009 issue of Physics Today, along with a feature article about superconducting qubits. The article discusses our work on arbitrary state generation in a harmonic oscillator (Hofheinz et al., Nature 459, 546-549 (2009). See publications.) as well as work from the Schoelkopf group at Yale. More recently, the photo was featured again on the cover of Quantum Measurement and Control by Wiseman and Milburn.

Current Research

Our research goal is to build a quantum computer using superconductors. Much of our effort is devoted to understanding the basic physics of decoherence (error) mechanisms in Josephson junction devices. Pictured below is a wafer with test dies that we use to measure two-qubit logic gates.

Sample qubit wafer

Our group is part of the California Nanosystems Institute.