arXiv:1804.10252 · Physical Review A

Weak-value amplification of photon-number operators in the optomechanical interaction

Sergio Carrasco, Miguel Orszag

Published Jan 2, 2019• 14 citations

Abstract

An experimental proposal is presented in which dark port postselection together with weak measurements are used to enlarge the radiation pressure effect of a single photon on a mechanical oscillator placed in the middle of a Fabry-P\'erot cavity and initialized in the ground state. By preparing and postselecting the photon (the system) in two quasiorthogonal states, the weak value of the radiation force operator can lie outside the eigenvalue spectrum, producing a large shift on the wave function of the mechanical oscillator (the measuring device) in the position representation. Consequently, the effect of a single photon on the average position of the oscillator can be amplified as compared to the effect caused by a photon without postselection, i.e., only preselected. The strong measurement scenario is also analyzed. In this case, a higher amplification effect is achieved and the mean position of the oscillator can reach the level of the zero-point fluctuations, but the postselection probabilities are smaller. Finally, the situation in which the oscillator starts in a thermal equilibrium state is studied. In this case, the amplification of the average position remains the same, i.e., proportional to the weak value, but the signal-to-noise ratio is reduced by a factor that depends on the average number of thermal phonons.

DOI: 10.1103/physreva.99.013801

Related papers

Strange weak values of photon number operators in the optomechanical interaction

Sergio Carrasco, Miguel Orszag

An interferometric experiment is proposed in order to measure the radiation force exerted by a single photon on a nano mechanical oscillator placed in the middle of a Fabry-P\'erot cavity. The force is measured by observing the shift given to the probability density function of the position of the oscillator, using weak measurements and post-selection of photons. We show that this shift is proportional to the weak value of the operator that accounts for the difference of photons between both sides of the cavity. For single-photon states, this operator has eigenvalues 1 or -1, depending on the side of the cavity in which is the photon, but the weak value can exceed by far this range. Thus, by preparing and post-selecting the photon in two nearly orthogonal states the weak value is increased and the radiation effect of a single photon turns out to be much larger than the pressure exerted by a photon without post-selection. This opens the possibility to study weak values of number operators in optomechanics and the radiation effect in pre- and post-selected ensembles.

Apr 26, 20180 citations

Implementation of weak measurement amplification with the weak coherent light and optomechanical system

Gang Li, Wen Yang

Abstract Most studies for postselected weak measurement in optomechanical system focus on using a single photon as a measured system. However, we find that using weak coherent light instead of a single photon can also amplify the mirror’s position displacement of one photon. In the weak value amplification (WVA) regime, the weak value of one photon can lie outside the eigenvalue spectrum, proportional to the difference of the mirror’s position displacement between the successful and failed postselection and its successful postselection probability is dependent of the mean photon number of the coherent light and improved by adjusting it accordingly. Outside the WVA regime, the amplification limit can reach the level of the vacuum fluctuations, and when the mean photon number and the optomechanical coupling parameter are selected appropriately, its successful postselection probability becomes higher, which is beneficial to observe the maximum amplification value under the current experimental conditions. This result breaks the constraint that it is difficult to detect outside the WVA regime. This opens up a new regime for the study of a single photon nonlinearity in optomechanical system.

arXiv:2104.03561Journal of Physics B Atomic Molecular and Optical PhysicsJun 9, 20212 citations

Estimation of an optomechanical parameter via weak-value amplification

Sergio Carrasco, Miguel Orszag

In this article we present an experimental proposal for the estimation of an optomechanical parameter in the presence of noise. The estimation is based on the technique of weak-value amplification which can enlarge the radiation pressure effect of a single photon on a mechanical oscillator. In our setup we show that the weak-value amplification technique is preferable for the estimation over a method that relies on a strong measurement with postselection because the first method does not require a good prior knowledge of the parameter we wish to estimate, while both strategies reach the same level of precision from a Fisher information perspective. In the presence of strongly correlated noise, the weak-value amplification method is preferable, from a Fisher information perspective, than a standard measurement strategy that does not employ postselection and that is affected by the same type of noise.

arXiv:1902.09247Physical Review AApr 11, 20226 citations

Amplification of mechanical quadratures using weak values

Sergio Carrasco, Miguel Orszag

Abstract An interferometric arrangement is proposed in which the technique of weak value amplification is implemented in order to enlarge the effect of a single photon on the quadratures of a movable mirror of an optical cavity. The photon interacts weakly with the mirror via radiation pressure and is postselected in the dark port of the interferometer. The real and imaginary parts of weak values of angular momentum type photonic operators produce an amplification of the mirror quadratures, which is large as compared to the scenario in which all photons are taken into consideration, i.e. when no postselection is performed. The effect is studied both for a mirror initialized in a thermal and coherent states. For a thermal state, the weak value amplification effect is boosted with the number of particles of the mirror, which occurs due to the imaginary part of the weak values.

arXiv:2202.00750Physica ScriptaMay 31, 20221 citation

Weak measurement amplification based on thermal noise effect

Gang Li, Tao Wang, He‐Shan Song

Abstract Most studies for postselected weak measurement focus on using the pure Gaussian state as a pointer, which can only give an amplification limit reaching the level of the ground state fluctuation. When the pointer is initialized in a thermal state, we find that the amplification limit after the postselection can reach the level of thermal fluctuation, indicating that the amplification effect achieving the level of thermal fluctuation is also increased with the temperature growth, and also that the amplification mechanism is different from that with pure Gaussian-state pointer. To illustrate these results, we propose two schemes to implement room temperature amplification of the mechanical oscillator’s displacement caused by a single photon in the optomechanical system. The two schemes both enhance the mechanical oscillator’s original displacement by nearly seven orders of magnitude, attaining sensitivity to displacements of ∼0.26 nm. Such amplification effect can be used to observe the impact of a single photon on a room temperature mechanical oscillator, which is hard to detect in traditional measurement.

arXiv:1507.00850Journal of Physics B Atomic Molecular and Optical PhysicsJan 20, 20201 citation

Postselected weak measurement based on thermal noise effect

Gang Li, Tao Wang, Shuang Xu +1 more

Most studies for postselected weak measurement focus on using pure Gaussian state as a pointer, which can only give an amplification limit reaching the ground state fluctuation. In this paper we use the thermal state pointer. We find that its amplification limit can reach thermal fluctuations and we also give the amplification mechanism different from the one with pure Gaussian state pointer. To illustrate the results, we propose two schemes to implement room temperature amplification of the mechanical oscillator's displacement caused by one photon in optomechanical system. The two schemes can both enhance the original displacement by nearly seven orders of magnitude, attaining sensitivity to displacements of ~ 0.26 nm. Such amplification effect can be used to observe the impact of a single photon on a room temperature mechanical oscillator which is impossible to detect in traditional measurement.

Jul 3, 20150 citations