[论文解读] Engineered dissipative reservoir for microwave light using circuit optomechanics

L. D. Tóth, Nathan Bernier+4 more|arXiv (Cornell University)|Feb 16, 2016

Mechanical and Optical Resonators被引用 3

一句话总结

该论文在微波电路光机械系统中展示了反向耗散机制，其中机械振子作为微波光子的低温、工程化耗散库。通过调控机械阻尼，作者实现了微波场的实时放大与去放大，观察到参量不稳定性（masing），并实现了低噪声、相位保持的放大器，为量子微波操控与纠缠开辟了新途径。

ABSTRACT

Isolation of a system from its environment is often desirable; however, dissipation can also be a useful resource. Remarkably, engineered dissipation enables the preparation and stabilization of quantum states of atoms, ions or superconducting qubits. This is achieved by a suitably engineered coupling to a dissipative cold reservoir formed by electromagnetic modes. Similarly, in the field of cavity electro- and optomechanics the control over mechanical oscillators utilizes the inherently cold dissipative nature of the electromagnetic degree of freedom. Breaking from this paradigm, recent theoretical work has considered the opposite regime in which the dissipation of the mechanical oscillator dominates and provides a cold dissipative reservoir to the electromagnetic mode. Here we report the experimental realization of this reversed dissipation regime in a microwave cavity optomechanical system and realize a quasi-instantaneous, cold reservoir for microwave light. We evidence this regime by decreasing or increasing the damping rate of the cavity on demand, that corresponds to amplification and de-amplification of the microwave field. Additionally, we observe the onset of parametric instability, i.e. the stimulated emission of microwaves (masing). Moreover, we employ the engineered cold reservoir to implement a low-noise, large-gain phase-preserving amplifier. Beyond offering the manipulation of microwave fields, such a dissipative reservoir for microwave light, when coupled to multiple cavity modes, forms the basis of microwave entanglement schemes, electromechanical amplifiers with unlimited gain-bandwidth product and dissipative quantum phase transitions. Equally important, combining such reservoir-mediated interaction with coherent dynamics allows for the realization of non-reciprocal devices, which would extend the available toolbox of quantum-limited microwave manipulation techniques.

研究动机与目标

• 实现一种反向耗散机制，其中机械阻尼占主导地位，并作为微波光子的低温库。
• 通过机械振子耦合，实现对微波场阻尼速率的动态控制。
• 利用工程化库实现低噪声、大增益、相位保持的放大器。
• 探索此类库在生成微波纠缠和实现非互易器件方面的潜力。

提出的方法

• 利用强耦合的超导微波腔与机械振子的微波腔光机械系统。
• 通过调控机械振子的阻尼率，使其作为电磁模的可调谐、低温库。
• 通过时间依赖的机械耗散控制，诱导微波场的放大或去放大。
• 当库被调谐至共振时，通过受激微波发射观察到参量不稳定性（masing）。
• 通过利用库介导的相互作用，实现低噪声相位保持放大器，噪声最小化。
• 将该框架扩展至多模系统，以实现纠缠和量子极限器件的潜在应用。

实验结果

研究问题

• RQ1 能否在电路光机械系统中工程化机械耗散，使其作为微波光子的低温库？
• RQ2 对机械阻尼的动态控制如何影响微波场的放大与去放大？
• RQ3 工程化库在微波系统中实现参量不稳定性（masing）方面发挥何种作用？
• RQ4 能否利用库介导的相互作用构建低噪声、高增益的相位保持放大器？
• RQ5 此类库对耗散量子相变和非互易微波器件有何影响？

主要发现

• 实验实现了反向耗散机制，其中机械振子作为微波光子的低温、工程化库。
• 微波腔的阻尼率可按需可控地增加或减少，从而实现对微波场的放大与去放大。
• 当库被共振耦合时，实验观察到参量不稳定性——表现为受激微波发射（masing）。
• 成功实现了低噪声、大增益的相位保持放大器，利用库介导的相互作用。
• 工程化库使生成微波纠缠和实现非互易微波器件成为可能。
• 该系统为耗散量子相变和具有无限增益带宽积的机电放大器奠定了基础。