SESSION 10: Quantum metrology

Chair: (Carlton M. Caves)
8:30am - 9:15amLee McCuller, Massachusetts Institute of Technology (invited)
Improving the sensitivity of Advanced LIGO with squeezed light
Abstract. The upcoming observing run 3 of Advanced LIGO will include quantum squeezed light at both observatories to improve sensitivity. This talk will detail the ongoing commissioning, as well as the technical requirements driving the design and control of audio-band squeezed light sources for gravitational wave optical interferometers. In addition, R&D is ongoing to demonstrate frequency dependent squeezed vacuum at 50Hz using optical filter cavities. Such an implementation will allow LIGO to reduce quantum radiation pressure noise below the standard quantum limit to achieve improvements spanning its observation band.
9:15am - 9:45amBaochen Wu, University of Colorado JILA
Towards spin-squeezed matter-wave interferometry
Abstract. Quantum entanglement permits the creation of spin-squeezed states where the fundamental quantum noise of one atom can be partially cancelled by another atom. Spin-squeezed states are particularly promising for enhancing precision measurements beyond the standard quantum limit for unentangled atoms. We have previously demonstrated 18 dB of squeezing (Cox et al, PRL, 116, 093602) with cavity-assisted non-demolition measurements in 87Rb atoms. Here we present our recent efforts towards building an intracavity, guided matter-wave interferometer in which spin-squeezing will be mapped to momentum states. This could help pave the way for better determinations of fundamental constants, more precise inertial sensors, and enhanced searches for dark matter.
9:45am - 10:15amKatherine McCormick, University of Colorado
Sensing near the Heisenberg limit with a trapped-ion mechanical oscillator
Abstract. Developing tools for precisely controlling and measuring the motion of a trapped ion could contribute to several possible applications, such as improving fidelities of quantum computations, opening up new avenues for quantum simulations and using ions as quantum-mechanical sensors in searches for new physics. I will discuss recent work aimed at characterizing and improving the level of motional coherence in trapped-ion systems, and present potential extensions for precision measurement applications. First, I will present results on the generation of oscillator number states up to n = 100 and superpositions of the form |0⟩+|n⟩, with n up to 18. These superposition states are used to measure the motional frequency with a sensitivity that ideally follows the 1/n Heisenberg scaling. Second, we investigate the spectrum of motional frequency noise using a series of coherent displacements of the motion of the ion, with features similar to Ramsey and dynamical decoupling sequences. These techniques, while demonstrated in a trapped-ion system, should be widely adaptable to other quantum-mechanical harmonic oscillators.

SQuInT Chief Organizer
Akimasa Miyake, Associate Professor

SQuInT Local Organizers
Rafael Alexander, Postdoctoral Fellow
Chris Jackson, Postdoctoral Fellow

SQuInT Administrator
Gloria Cordova
505 277-1850

SQuInT Assistant
Wendy Jay

SQuInT Founder
Ivan Deutsch, Regents' Professor, CQuIC Director

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