Quantum Measurement and Control of a Mechanical Resonator

Location: 
Mann Engineer Student Center - Room 107 (located in Dunham Lab – 10 Hillhouse Ave) See map
10 Hillhouse Avenue
New Haven, CT 06511

Special Solid State & Optics Seminar Series

sponsored by “The Flint Fund Series on Quantum Devices and Nanostructures”

Monday, January 28, 2019

 2:00 PM-3:30 PM

FOE Mann Student Center

David Mason

The Center for Hybrid Quantum Networks (Hy-Q) at The University of Copenhagen, Denmark

Quantum Measurement and Control of a Mechanical Resonator

Quantum-limited displacement measurements are key to physics ranging from gravitational wave detection to control of quantum technologies.  Here, I’ll present recent work which explores such measurements of a macroscopic, ultracoherent mechanical resonator.  By measuring the resonator as fast as it decoheres, we reach within 35% of the Heisenberg imprecision-backaction limit– a regime which allows us to cool the resonator to its ground state by applying classical feedback.  Furthermore, by exploiting quantum correlations, we achieve, for the first time, a displacement sensitivity below the Standard Quantum Limit (by 1.5dB).  Finally, I’ll discuss recent work in which we analyze this highly-efficient measurement within the framework of continuous quantum measurement and quantum trajectories.  I’ll show how the effect of our measurement is to project the system into a conditional coherent state of high purity, and introduce a retrodiction-verification protocol which allows us to verify this purity directly.  This verification technique even allows for direct visualization of the measurement-induced collapse of our conditional state.

Hosted by Prof. Peter Rakich

Applied Physics, Yale University

Event time: 
Monday, January 28, 2019 - 2:00pm
Sponsor: 
The Flint Fund Series on Quantum Devices and Nanostructures”
Presented By: 
David Mason, The Center for Hybrid Quantum Networks (Hy-Q) at The University of Copenhagen, Denmark
Hosted By: 
Prof. Peter Rakich