Date:
Mon, 21/03/202212:00-13:30
Location:
Levin building, Lecture Hall No. 8
Speaker: John Howell (HUJI)
Abstract:
The burgeoning field of quantum metrology seeks to find “quantum advantages” over
existing classical measurement schemes. Owing to its importance in gyroscopes and
gravitational wave detection as well as its fundamental nature in all branches of
interferometry, phase estimation beyond the standard quantum limit has been the
prototypical example [1–3]. Pragmatically, due to loss, quantum phase estimation
techniques have, so far, only offered a few percent improvement over the standard
quantum limit in the few-photon regime [4] or a few dB improvement in the high power
regime [5]. However, what if phase estimation for a class of experiments is suboptimal?
Depending on the measurement apparatus, phase estimation may have different
fundamental limits than frequency estimation [6]. I will discuss a new type of gyroscope
that relies on an ultra-steep, frequency-dependent gain measurement rather than
performing phase estimation in a passive gyroscope. With this technique we can achieve
orders of magnitude improvement below the phase-estimation standard quantum limit of a
single-loop Sagnac interferometer of the same size. I will discuss important insights into
a long-debated open question about the role of Doppler shifts in the Sagnac effect.
[1] Carlton M Caves, “Quantum-mechanical noise in an interferometer,” Physical Review D 23,
1693 (1981).
[2] MJ Holland and K Burnett, “Interferometric detection of optical phase shifts at the heisenberg
limit,” Physical review letters 71, 1355 (1993).
[3] Agedi N. Boto, Pieter Kok, Daniel S. Abrams, Samuel L. Braunstein, Colin P. Williams, and
Jonathan P. Dowl- ing, “Quantum interferometric optical lithography: Exploiting entanglement to
beat the diffraction limit,” Phys. Rev. Lett. 85, 2733–2736 (2000).
[4] GJ Pryde, S Slussarenko, MM Weston, HM Chrzanowski, LK Shalm, VB Verma, and SW Nam,
“Unconditional shot-noise-limit violation in photonic quantum metrology,” in Conference on Lasers
and Electro-Optics/Pacific Rim (Optical Society of America, 2018) pp. Th4J–1.
[5] Benjamin J Lawrie, Paul D Lett, Alberto M Marino, and Raphael C Pooser, “Quantum sensing
with squeezed light,” ACS Photonics 6, 1307–1318 (2019).
[6] Umberto Bortolozzo, Stefania Residori, and John C Howell, “Precision doppler measurements
with steep dis- persion,” Optics letters 38, 3107–3110 (2013).
Abstract:
The burgeoning field of quantum metrology seeks to find “quantum advantages” over
existing classical measurement schemes. Owing to its importance in gyroscopes and
gravitational wave detection as well as its fundamental nature in all branches of
interferometry, phase estimation beyond the standard quantum limit has been the
prototypical example [1–3]. Pragmatically, due to loss, quantum phase estimation
techniques have, so far, only offered a few percent improvement over the standard
quantum limit in the few-photon regime [4] or a few dB improvement in the high power
regime [5]. However, what if phase estimation for a class of experiments is suboptimal?
Depending on the measurement apparatus, phase estimation may have different
fundamental limits than frequency estimation [6]. I will discuss a new type of gyroscope
that relies on an ultra-steep, frequency-dependent gain measurement rather than
performing phase estimation in a passive gyroscope. With this technique we can achieve
orders of magnitude improvement below the phase-estimation standard quantum limit of a
single-loop Sagnac interferometer of the same size. I will discuss important insights into
a long-debated open question about the role of Doppler shifts in the Sagnac effect.
[1] Carlton M Caves, “Quantum-mechanical noise in an interferometer,” Physical Review D 23,
1693 (1981).
[2] MJ Holland and K Burnett, “Interferometric detection of optical phase shifts at the heisenberg
limit,” Physical review letters 71, 1355 (1993).
[3] Agedi N. Boto, Pieter Kok, Daniel S. Abrams, Samuel L. Braunstein, Colin P. Williams, and
Jonathan P. Dowl- ing, “Quantum interferometric optical lithography: Exploiting entanglement to
beat the diffraction limit,” Phys. Rev. Lett. 85, 2733–2736 (2000).
[4] GJ Pryde, S Slussarenko, MM Weston, HM Chrzanowski, LK Shalm, VB Verma, and SW Nam,
“Unconditional shot-noise-limit violation in photonic quantum metrology,” in Conference on Lasers
and Electro-Optics/Pacific Rim (Optical Society of America, 2018) pp. Th4J–1.
[5] Benjamin J Lawrie, Paul D Lett, Alberto M Marino, and Raphael C Pooser, “Quantum sensing
with squeezed light,” ACS Photonics 6, 1307–1318 (2019).
[6] Umberto Bortolozzo, Stefania Residori, and John C Howell, “Precision doppler measurements
with steep dis- persion,” Optics letters 38, 3107–3110 (2013).