Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Optics Communications

Non-classical effect of quantum non-demolition measurement in presence of parametric amplification

M. Sebawe Abdalla, Jan Peřina, J. Křepelka

Published Apr 13, 2009• 7 citations
Publisher
DOI
10.1016/j.optcom.2009.03.053

Related papers

Quantum non-demolition measurements with an optical parametric amplifier

Philip J. Cameron-Smith, Matthew J. Collett, Daniel F. Walls

Optics Communications•Sep 1, 1993•14 citations

Parametric amplification of images: classical and quantum effects

Éric Lantz, F. Devaux, Jean-Luc Blanchet

•Sep 12, 2007•0 citations

Detuned mechanical parametric amplification as a quantum non-demolition measurement

Alex Szorkovszky, A A Clerk, Andrew C. Doherty +1 more

Recently it has been demonstrated that the combination of continuous position detection with detuned parametric driving can lead to significant steady-state mechanical squeezing, far beyond the 3 dB limit normally associated with parametric driving. In this work, we show the close connection between this detuned scheme and quantum non-demolition (QND) measurement of a single mechanical quadrature. In particular, we show that applying an experimentally realistic detuned parametric drive to a cavity optomechanical system allows one to effectively realize a QND measurement despite being in the bad-cavity limit. In the limit of strong squeezing, we show that this scheme offers significant advantages over standard backaction evasion, not only by allowing operation in the weak measurement and low efficiency regimes, but also in terms of the purity of the mechanical state.

arXiv:1401.6215•New Journal of Physics•Apr 24, 2014•16 citations

Quantum statistics of parametric amplification

Ladislav Mišta, Jan Peřina

Czechoslovak Journal of Physics•Apr 1, 1978•34 citations

Quantum measurement and control of a mechanical parametric oscillator

Alex Szorkovszky

Unlike classical systems, the very act of observing quantum systems perturbs their behaviour. This introduces noise, which imposes limits on the knowledge that can be obtained through measurement. Certain measurement techniques, known generally as quantum non-demolition (QND) measurements, exist to circumvent this noise. An alternative method to evade backaction noise is to amplify the observable of interest above the noise. However, this generally leaves the system in a different state, and is therefore not considered a QND measurement. In this thesis, I examine the benefits of amplification for various kinds of measurement of mechanical harmonic oscillators which, at the micrometre and nanometre scale, comprise an emerging quantum technology. For this prototypical case, modulation of the spring constant, also known as parametric amplification, is a well-studied noiseless amplification technique. Using the theory of trajectories developed in the field of quantum optics, I show that a weak measurement combined with a detuned parametric drive achieves the same ends as strong QND measurement. Namely, it allows backaction-free observation of one quadrature of mechanical motion, and through this, quantum squeezing below the quantum zero-point motion. This equivalence is experimentally confirmed in the classical limit using an optically detected, electrically modulated cantilever. In addition, I analyse similar amplification enhanced techniques for quantum entanglement and quantum tomography. These results are applicable to research in quantum optomechanics and electromechanics, and can be translated to other kinds of quantum harmonic oscillators, such as microwave cavities.

•Nov 30, 2014•1 citation

Quantum non-demolition measurement of the photon number: an application to radiometry

Stefania Castelletto, Ivo Pietro Degiovanni, Maria Luisa Rastello

This paper proposes a realistically feasible experiment, within the realm of existing technology and proved techniques, to measure the mean photon number of a coherent source by means of a quantum non-demolition scheme, exploiting the parametric amplification of correlated photons in χ (2) media. We deduce the number of photons of an input source interacting with a high-intensity pump field in a nonlinear crystal, using as the probe the shift in the quadrature amplitude of the pump beam induced by the source under measurement. We perform a theoretical evaluation of the noise level associated with this measurement and compare it with the quantum limit. We explore the possible implications of this method for radiometry.

Journal of Optics B Quantum and Semiclassical Optics•Feb 1, 2001•2 citations
Recently it has been demonstrated that the combination of continuous position detection with detuned parametric driving can lead to significant steady-state mechanical squeezing, far beyond the 3 dB limit normally associated with parametric driving. In this work, we show the close connection between this detuned scheme and quantum non-demolition (QND) measurement of a single mechanical quadrature. In particular, we show that applying an experimentally realistic detuned parametric drive to a cavity optomechanical system allows one to effectively realize a QND measurement despite being in the bad-cavity limit. In the limit of strong squeezing, we show that this scheme offers significant advantages over standard backaction evasion, not only by allowing operation in the weak measurement and low efficiency regimes, but also in terms of the purity of the mechanical state.
Unlike classical systems, the very act of observing quantum systems perturbs their behaviour. This introduces noise, which imposes limits on the knowledge that can be obtained through measurement. Certain measurement techniques, known generally as quantum non-demolition (QND) measurements, exist to circumvent this noise. An alternative method to evade backaction noise is to amplify the observable of interest above the noise. However, this generally leaves the system in a different state, and is therefore not considered a QND measurement. In this thesis, I examine the benefits of amplification for various kinds of measurement of mechanical harmonic oscillators which, at the micrometre and nanometre scale, comprise an emerging quantum technology. For this prototypical case, modulation of the spring constant, also known as parametric amplification, is a well-studied noiseless amplification technique. Using the theory of trajectories developed in the field of quantum optics, I show that a weak measurement combined with a detuned parametric drive achieves the same ends as strong QND measurement. Namely, it allows backaction-free observation of one quadrature of mechanical motion, and through this, quantum squeezing below the quantum zero-point motion. This equivalence is experimentally confirmed in the classical limit using an optically detected, electrically modulated cantilever. In addition, I analyse similar amplification enhanced techniques for quantum entanglement and quantum tomography. These results are applicable to research in quantum optomechanics and electromechanics, and can be translated to other kinds of quantum harmonic oscillators, such as microwave cavities.
This paper proposes a realistically feasible experiment, within the realm of existing technology and proved techniques, to measure the mean photon number of a coherent source by means of a quantum non-demolition scheme, exploiting the parametric amplification of correlated photons in χ (2) media. We deduce the number of photons of an input source interacting with a high-intensity pump field in a nonlinear crystal, using as the probe the shift in the quadrature amplitude of the pump beam induced by the source under measurement. We perform a theoretical evaluation of the noise level associated with this measurement and compare it with the quantum limit. We explore the possible implications of this method for radiometry.