### Session P26: Superconducting Qubits: Materials / Nanomechanical Resonators

8:00 AM–11:00 AM, Wednesday, March 17, 2010
Room: D136

Chair: David Schuster, Yale University

Abstract ID: BAPS.2010.MAR.P26.15

### Abstract: P26.00015 : A macroscopic mechanical resonator operated in the quantum limit

10:48 AM–11:00 AM

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#### Authors:

Aaron O'Connell
(University of California, Santa Barbara - Physics)

Michael Lenander
Erik Lucero
Matteo Mariantoni
Matthew Neeley
Daniel Sank
Haohua Wang
Martin Weides
James Wenner
Tsuyoshi Yamamoto
Yi Yin
John Martinis
Andrew Cleland

The observation of quantum effects in a macroscopic mechanical resonator is hindered by the difficulty in cooling to the quantum ground state, and in making a system that displays adequate coherence times. We are able to meet these challenges in a novel system comprising a superconducting phase qubit coupled to a high frequency (6 GHz) micromechanical dilatational resonator. Using this coupled system, we place an upper bound on the minimum average phonon occupation number of the mechanical resonator $\langle n \rangle < 0.07$, showing that the resonator is in its quantum ground state. Furthermore, we use the qubit to both create and measure a single phonon state in the resonator. Using this ability, the energy decay and phase coherence times of the resonator are extracted. Additionally, we excite the resonator directly with a classical microwave source, demonstrably creating a coherent state in the mechanical resonator.

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2010.MAR.P26.15