基於囚禁離子系統中的腔體量子電動力學

Abstract

本研究旨在探討使用光鑷在大型離子晶體中操作聲子自由度的理論研究。我們的方法是利用光鑷選擇性地固定特定離子，創造出阻礙聲波傳播的屏障。這樣一來，我們可以模擬一維聲腔，其中這些屏障之間的一部分離子對有效腔體的局部運動模式做出貢獻。

為了瞭解腔體的特性，我們計算了模態頻譜、損耗率和馬可夫性。根據我們對這些模式施加藍邊帶或紅邊帶躍遷，我們可以將腔體模態激發或阻抑。在激發的情況下，我們觀察到聲子雷射行為，包括雷射閾值的出現、接近泊松分佈的統計特性、相干性、線寬窄化，以及引人入勝的效應，如模式競爭和多穩定性。另一方面，在阻抑的情況下，我們發現某些次都卜勒冷卻（電磁誘發透明冷卻）技術仍適用於局部模式。因此，與不使用光鉗的情況相比，可以更有效且節省成本地冷卻子陣列。

我們提出的系統為研究腔體量子電動力學提供了聲學類比，為聲子媒介的量子操作、通信和計算開創了道路。

In this study, we propose a theoretical investigation into the manipulation of phononic degrees of freedom using optical tweezers in a large ionic crystal. Our approach involves the use of optical tweezers to selectively immobilize specific ions, creating barriers that impede the propagation of acoustic waves. By doing so, we can emulate a one-dimensional acoustic cavity, where a subset of ions between these barriers contributes to the local motional modes of the effective cavity.

To gain insights into the characteristics of the cavity, we calculate the mode spectrum, loss rates, and the Markovianity of the cavity. Depending on whether we apply blue or red sideband transitions to these modes, we can either pump or damp the cavity mode excitations. In the case of pumping, we observe phonon lasing behavior, including the emergence of lasing thresholds, near-Poisson statistics, correlations, line-narrowing, as well as intriguing effects such as mode competition and multi-stability. On the other hand, in the case of damping, we discover that certain sub-Doppler cooling (electromagnetically-induced-transparency cooling) techniques remain applicable to the local modes. Consequently, the sub-array can be cooled more efficiently and economically compared to scenarios without the use of tweezers.

Our proposed system provides an acoustic equivalent for exploring cavity quantum electrodynamics, opening up possibilities for quantum manipulation, communication, and computation mediated by phonons.