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arXiv · 2607.20905

Multicritical dissipative phase transitions manipulated by dipole--dipole interactions

Jia-Xin Wang·Qian Bin·Jing-Jing Cao·Xin-You Lü
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Abstract

Precise control of criticality in superradiant phase transitions is essential for quantum state engineering and the simulation of nonequilibrium phase transitions. Here, we investigate theoretically multicritical phenomena in a dissipative two-Rydberg-atom cavity--QED system. The intrinisic dipole--dipole interaction between the two Rydberg atoms restructures the energy-level landscape of the atomic subsystem, thereby significantly modifying the boundary of the continuous second-order superradiant phase transition, and shifting both the phase boundary and the multicritical point toward weaker atom--cavity strengths. For sufficiently strong dipole--dipole interactions, the continuous second-order phase transition and the multicritical point both disappear, leaving only a discontinuous first--order phase transition that enables the emergence of a superradiant phase even at arbitrarily weak atom--cavity coupling. This work is of fundamental interest for studying dissipative quantum phase transitions, with potential implications for quantum precision measurement and quantum sensing.

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Jia-Xin Wang, Qian Bin, Jing-Jing Cao, Xin-You Lü. 2026-07-23. Multicritical dissipative phase transitions manipulated by dipole--dipole interactions. https://arxiv.org/abs/2607.20905

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