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arXiv · 1910.00747

Interplay of quantum phase transition and flat band in hybrid lattices

Gui-Lei Zhu·Hamidreza Ramezani·Clive Emary·Jin-Hua Gao·Ying Wu·Xin-You Lü
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Abstract

We investigate the interplay of superradiant phase transition (SPT) and energy band physics in an extended Dicke-Hubbard lattice whose unit cell consists of a Dicke model coupled to an atomless cavity. We found in such a periodic lattice the critical point that occurs in a single Dicke model becomes a critical region that is periodically changing with the wavenumber $k$. In the weak-coupling normal phase of the system we observed a flat band and its corresponding localization that can be controlled by the ground-state SPT. Our work builds the connection between flat band physics and SPT, which may fundamentally broaden the regimes of many-body theory and quantum optics.

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Gui-Lei Zhu, Hamidreza Ramezani, Clive Emary, Jin-Hua Gao, Ying Wu, Xin-You Lü. 2019-10-02. Interplay of quantum phase transition and flat band in hybrid lattices. https://doi.org/10.1103/physrevresearch.2.033463

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