Locally-acting mirror Hamiltonians

Influence functional for two mirrors interacting via radiation pressure

We study the effective dynamics of two mirrors, forming an optical cavity, and interacting with the cavity field via radiation pressure. We pursue a perturbative influence functional approach to trace out the degrees-of-freedom of the field, and obtain the second order effective action for the system composed by the mirrors. We find that the interaction between the mirrors is mediated by pairs of field modes, which combine in such a way to give rise to two different interaction channels. We find that the quantum and thermal fluctuations of the cavity field result in coloured, Gaussian stochast…

Quantum-limited force measurement with an optomechanical device

We study the detection of weak coherent forces by means of an optomechanical device formed by a highly reflecting isolated mirror shined by an intense and highly monochromatic laser field. Radiation pressure excites a vibrational mode of the mirror, inducing sidebands of the incident field, which are then measured by heterodyne detection. We determine the sensitivity of such a scheme and show that the use of an entangled input state of the two sideband modes improves the detection, even in the presence of damping and noise acting on the mechanical mode.

Quantum thermal machine acting on a many-body quantum system: role of correlations in thermodynamic tasks

We study the functioning of a three-level thermal machine when acting on a many-qubit system, the entire system being placed in an electromagnetic field in a stationary out-of-thermal-equilibrium configuration. This realistic setup stands in between the two so-far explored cases of single-qubit and macroscopic object targets, providing information on the scaling with system size of purely quantum properties in thermodynamic contexts. We show that, thanks to the presence of robust correlations among the qubits induced by the field, thermodynamic tasks can be delivered by the machine both locall…

Quantum matter wave dynamics with moving mirrors

When a stationary reflecting wall acting as a perfect mirror for an atomic beam with well defined incident velocity is suddenly removed, the density profile develops during the time evolution an oscillatory pattern known as diffraction in time. The interference fringes are suppressed or their visibility is diminished by several effects such as averaging over a distribution of incident velocities, apodization of the aperture function, atom-atom interactions, imperfect reflection or environmental noise. However, when the mirror moves with finite velocity along the direction of propagation of the…

利用反射边界抑制悬浮光力学中的反作用噪声

Backaction suppression in levitated optomechanics using reflective boundaries

本文理论上证明，利用反射边界可显著抑制悬浮光力学系统中激光诱导的反作用噪声，并以球面镜为例验证了该效应，满足海森堡探测极限。

闭时间路径方法用于光学机械反作用问题

Closed-time-path approach to the optomechanical back-reaction problem

本文提出闭时间路径方法研究光学机械系统中量子场与运动镜片通过辐射压力的相互作用，推导了运动镜片的动力学有效作用，验证了光学反作用力与场中粒子创建的能量平衡。