2023-06-22 カリフォルニア工科大学(Caltech)
◆このセンサは、量子情報を保存するために使用されることが期待されています。フォノンと呼ばれる音の粒子を利用し、小さなデバイスによって量子情報を保存することができます。この研究は、量子コンピューティングや医療画像などの分野で重要な役割を果たす可能性があります。
＜関連情報＞
- https://www.caltech.edu/about/news/new-device-opens-door-to-storing-quantum-information-as-sound-waves
- https://www.nature.com/articles/s41567-023-02080-w
長寿命フォノンのための量子電気機械インターフェース A quantum electromechanical interface for long-lived phonons
Alkim Bozkurt,Han Zhao,Chaitali Joshi,Henry G. LeDuc,Peter K. Day & Mohammad Mirhosseini
Nature Physics Published22: June 2023
DOI:https://doi.org/10.1038/s41567-023-02080-w
Abstract
In single crystals, the suppression of intrinsic loss channels at low temperatures leads to exceptionally long mechanical lifetimes. Quantum electrical control of such long-lived mechanical oscillators would enable the development of phononic memory elements, sensors and transducers. The integration of piezoelectric materials is one approach to introducing electrical control, but the challenges of combining heterogeneous materials lead to severely limited phonon lifetimes. Here we present a non-piezoelectric silicon electromechanical system capable of operating in the gigahertz frequency band. Relying on a driving scheme based on electrostatic fields and the kinetic inductance effect in disordered superconductors, we demonstrate a parametrically enhanced electromechanical coupling of g/2π = 1.1 MHz, sufficient to enter the strong-coupling regime with a cooperativity of C=1,200. In our best devices, we measure mechanical quality factors approaching Q ≈ 107, measured at low-phonon numbers and millikelvin temperatures. Despite using strong electrostatic fields, we find the cavity mechanics system in the quantum ground state, verified by thermometry measurements. Simultaneously achieving ground-state operation, long mechanical lifetimes and strong coupling sets the stage for employing silicon electromechanical devices in hybrid quantum systems and as a tool for studying the origins of acoustic loss in the quantum regime.
