Experiment Award

The award for outstanding achievements in quantum experimentation, as decided by the QCMC 2018 Award Committee, goes to Prof. Nergis Mavalvala, Prof. David McClelland, and Prof. Roman Schnabel. Professor McClelland and Professor Schnabel will each give a 45-minute award talk on Friday March 16.

Audio-band Squeezing and LIGOFollowing Caves 1981 proposal to use squeezed states of light to reduce quantum noise in laser interferometers [1], Slusher et al in 1985 produced the first experimental demonstration of squeezed light – 0.3 dB at 400 MHz sideband frequencies [2]. Over the next 17 years, great progress was made so by 2002, groups were regularly producing 6 or 7 dB of vacuum squeezing down to around 100 kHz. However, to be useful in a gravitational wave detector, squeezed vacuum states of at least 10db squeezing from 10Hz were required. Thus was borne the ’10 dB Consortium’ at the Australian National University (ANU) in 2003 - a commitment by the ANU, the Massachusetts Institute of Technology and the Albert Einstein Institute, Hannover, to deliver 10dB squeezing, from 10 Hz within 10 years. Nine years later, that goal was realised [3]. I will discuss the approach we took to reach this goal, refinements since then, early implementation of squeezing in LIGO and future directions.

[1] C.M. Caves, “Quantum-mechanical noise in an interferometer”, Phys.Rev.D23, 1693 (1981)
[2] R.E. Slusher et al, “Observation of Squeezed States Generated by Four-Wave Mixing in an Optical Cavity”, Phys.Rev.Lett. 55, 2409 (1985).
[3] M.S. Stefszky, et al, “Balanced homodyne detection of optical quantum states at audio-band frequencies and below”, Class.Quant. Grav.29, 145015 (2012).

Squeezed States of Light in the Gravitational-Wave Detector GEO600 Squeezed states of light cannot be described by a semi-classical model and belong to the class of nonclassical states. As proposed by C. Caves in 1981, they allow for the suppression of photon counting noise (shot-noise) in laser interferometers [1]. Shot noise indeed limits the sensitivity of all current and all envisioned (laser-interferometric) gravitational-wave (GW) detectors in significant parts of their signal frequency bands. This talk revisits the concept of squeezed light and summarizes the research and development that was done to realize the first turn-key squeezed-light source. This source was designed and completed by my group in 2010 at the Leibniz Universität Hannover [2]. Since then, it has been part of the GW detector GEO600 [3]. It is fully automated and provides strongly squeezed states over the full signal band of ground-based GW detectors from below 10 Hz to above 10 kHz. The source has now been used for almost 8 years to improve the sensitivity of GEO600 to regimes that could not be reached otherwise for different practical reasons. Due to the high readiness level of the squeezed light technology as developed in the past 15 years, the GW detectors Advanced LIGO and Advanced Virgo are currently being upgraded also with squeezed light although this step was not included in the initial designs.

[1] R. Schnabel, Squeezed states of light and their applications in laser interferometers, Physics Reports 684, 1–51 (2017)
[2] H. Vahlbruch, A. Khalaidovski, N. Lastzka, C. Gräf, K. Danzmann, R. Schnabel, The GEO600 squeezed light source, Class. Quantum Grav. 27, 084027 (2010)
[3] The LIGO Scientific Collaboration (J. Abadie et al.), A gravitational wave observatory operating beyond the quantum shot-noise limit, Nature Physics 7, 962 (2011)

Theory Award

The award for outstanding achievements in quantum theory, as decided by the QCMC 2018 Award Committee, goes to Prof. Carlton Caves. Professor Caves will give a 50-minute award talk on Friday March 16.

One physicist's crooked path from quantum optics to quantum information
Quantum information science has changed our view of quantum mechanics. Originally viewed as a nag, whose uncertainty principles restrict what we can do, quantum mechanics is now seen as a liberator, allowing us to do things, such as secure key distribution and efficient computations, that could not be done in the realistic world of classical physics. Yet there is one area, that of quantum limits on high-precision measurements, where the two faces of quantum mechanics remain locked in battle. I will trace the history of quantum-limited measurements, from the use of nonclassical light to improve the phase sensitivity of an interferometer, to the modern perspective on the role of entanglement in improving measurement precision.

Previous laureates:

1996: Charles Bennett, Carl Helstrom, Alexander Holevo, Horace Yuen
1998: Jeffrey Kimble, Peter Shor
2000: Paul Benioff, Christopher Monroe, David Wineland
2002: David Deutsch, Serge Haroche, Benjamin Schumacher
2004: Richard Jozsa, Prem Kumar
2006: Ignacio Cirac, Philippe Grangier, William Wootters, Peter Zoller
2008: Jeffrey Shapiro, Akira Furusawa, Anton Zeilinger
2010: Gerard Milburn, Masanao Ozawa, Christopher Fuchs, Alexander Lvovsky
2012: Jian-Wei Pan, Seth Lloyd
2014: Nicolas Gisin, Reinhard Werner
2016: Rainer Blatt, Artur Ekert




We would like to acknowledge the support provided by the US Army Research Office to help make this event possible.

QCMC 2018 Louisiana State University