Abstract :

Dicke, in his seminal work in 1954, showed that two-level atoms coupled to a common photon mode could exhibit superradiance. Dicke also suggested entangling two non interacting two level atoms. We propose extending this idea to many spins as a way to synthesize highly entangled two level systems. Interestingly, We find that subradiant states (dark states) belong to this category. Further they realize resonating valence bond states, well known in condensed matter physics. We explicitly bring out the RVB character, using Clebsch – Gordan (CG) coefficients analysis [1]. We also present a protocol to create and observe such RVB states experimentally. In the process we have also found an interesting quantum phase transition [2] in the Dicke model.

[1] R. GANESH, L. THEERTHAGIRI AND G BASKARAN, 10.1103/PhysRevA.96.033829
[2] R. GANESH, L. THEERTHAGIRI AND G. BASKARAN, arXiv:1803.03267 [1] (TO APPEAR IN SCIPOST PHYSICS).