Ultrastrong magnon–magnon coupling dominated by antiresonant interactions
Abstract
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.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- May 25, 2021
- Source ID
- 10.1038/s41467-021-23159-z
Entities
People
- Dmitry Turchinovich
- G. Timothy Noe Ii
- Guohong Ma
- Hiroyuki Nojiri
- Ikufumi Katayama
- Jun Takeda
- Junichiro Kono
- Kenji Hayashida
- Motoaki Bamba
- Nicolas Marquez Peraca
- Shixun Cao
- Takuma Makihara
- Wei Ren
- Xiaoxuan Ma
- Xinwei Li
- Zuanming Jin
Organizations
- Army Research Office
- National Natural Science Foundation of China