Spin State Dynamics in a Bichromatic Microwave Field: Role of Bright and Dark States in coupling with Reservoir

Engineering a squeezed phonon reservoir with a bichromatic driving of a quantum dot

We demonstrate how an acoustic phonon bath when coupled to a quantum dot with the help of a bichromatic laser field may effectively form a quantum squeezed reservoir. This approach allows to achieve an arbitrary degree of squeezing of the effective reservoir and it incorporates the properties of the reservoir into two parameters, which can be controlled by varying the ratio of the Rabi frequencies of the bichromatic field. It is found that for unequal Rabi frequencies, the effective reservoir may appear as a quantum squeezed field of ordinary or inverted harmonic oscillators. When the Rabi fre…

Bright bichromatic entanglement and quantum dynamics of sum frequency generation

We investigate the quantum properties of the well-known process of sum frequency generation, showing that it is potentially a very useful source of non-classical states of the electromagnetic field, some of which are not possible with the more common techniques. We show that it can produce quadrature squeezed light, bright bichromatic entangled states and symmetric and asymmetric demonstrations of the Einstein-Podolsky-Rosen paradox. We also show that the semiclassical equations totally fail to describe the mean-field dynamics when the cavity is strongly pumped.

Reservoir engineering of a mechanical resonator: generating a macroscopic superposition state and monitoring its decoherence

A deterministic scheme for generating a macroscopic superposition state of a nanomechanical resonator is proposed. The nonclassical state is generated through a suitably engineered dissipative dynamics exploiting the optomechanical quadratic interaction with a bichromatically driven optical cavity mode. The resulting driven dissipative dynamics can be employed for monitoring and testing the decoherence processes affecting the nanomechanical resonator under controlled conditions.

Generation of Squeezed States of Nanomechanical Resonators by Reservoir Engineering

An experimental demonstration of a non-classical state of a nanomechanical resonator is still an outstanding task. In this paper we show how the resonator can be cooled and driven into a squeezed state by a bichromatic microwave coupling to a charge qubit. The stationary oscillator state exhibits a reduced noise in one of the quadrature components by a factor of 0.5 - 0.2. These values are obtained for a 100 MHz resonator with a Q-value of 10$^4$ to 10$^5$ and for support temperatures of T $\approx$ 25 mK. We show that the coupling to the charge qubit can also be used to detect the squeezed st…

干涉增强的强场电离不对称性与明亮压缩真空

Interferometrically Enhanced Asymmetry in Strong-field Ionization with Bright Squeezed Vacuum

利用量子光统计控制强场电离隧道步骤，通过双频线性偏振场模拟显示，光电子动量分布不对称性显著增强，源于压缩真空场的非经典统计特性。

公共玻色子库中的谱扭转：两量子比特暗态保护的脆弱性

Spectral Twisting in a Common Bosonic Reservoir: Fragility of Two-Qubit Dark-State Protection

本研究揭示公共玻色子库中谱扭转效应，量化其导致两量子比特暗态保护泄漏的机制，并发现弱扭转下泄漏与谱交叉点参数呈二次标度关系。