Makihara Takuma, Hayashida Kenji, Noe Ii G Timothy, Li Xinwei, Marquez Peraca Nicolas, Ma Xiaoxuan, Jin Zuanming, Ren Wei, Ma Guohong, Katayama Ikufumi, Takeda Jun, Nojiri Hiroyuki, Turchinovich Dmitry, Cao Shixun, Bamba Motoaki, Kono Junichiro
Department of Physics and Astronomy, Rice University, Houston, TX, USA.
Department of Electrical and Computer Engineering, Rice University, Houston, TX, USA.
Nat Commun. 2021 May 25;12(1):3115. doi: 10.1038/s41467-021-23159-z.
Exotic quantum vacuum phenomena are predicted in cavity quantum electrodynamics systems with ultrastrong light-matter interactions. Their ground states are predicted to be vacuum squeezed states with suppressed quantum fluctuations owing to antiresonant terms in the Hamiltonian. However, such predictions have not been realized because antiresonant interactions are typically negligible compared to resonant interactions in light-matter systems. Here we report an unusual, ultrastrongly coupled matter-matter system of magnons that is analytically described by a unique Hamiltonian in which the relative importance of resonant and antiresonant interactions can be easily tuned and the latter can be made vastly dominant. We found a regime where vacuum Bloch-Siegert shifts, the hallmark of antiresonant interactions, greatly exceed analogous frequency shifts from resonant interactions. Further, we theoretically explored the system's ground state and calculated up to 5.9 dB of quantum fluctuation suppression. These observations demonstrate that magnonic systems provide an ideal platform for exploring exotic quantum vacuum phenomena predicted in ultrastrongly coupled light-matter systems.
在具有超强光与物质相互作用的腔量子电动力学系统中，预测存在奇异的量子真空现象。由于哈密顿量中的反共振项，其基态预计为量子涨落受到抑制的真空压缩态。然而，此类预测尚未实现，因为在光与物质系统中，反共振相互作用通常与共振相互作用相比可忽略不计。在此，我们报告了一种不寻常的、超强耦合的磁振子物质 - 物质系统，该系统可由一个独特的哈密顿量进行解析描述，其中共振和反共振相互作用的相对重要性可轻松调节，且后者可占据主导地位。我们发现了一个区域，其中反共振相互作用的标志——真空布洛赫 - 西格特位移，大大超过了共振相互作用产生的类似频移。此外，我们从理论上探索了该系统的基态，并计算出高达5.9分贝的量子涨落抑制。这些观察结果表明，磁振子系统为探索超强耦合光与物质系统中预测的奇异量子真空现象提供了一个理想平台。
