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arXiv · 2307.16743

Stability via symmetry breaking in interacting driven systems

Andrew Pocklington·Aashish A. Clerk
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Abstract

Photonic and bosonic systems subject to incoherent, wide-bandwidth driving cannot typically reach stable finite-density phases using only non-dissipative Hamiltonian nonlinearities; one instead needs nonlinear losses, or a finite pump bandwidth. We describe here a very general mechanism for circumventing this common limit, whereby Hamiltonian interactions can cut-off heating from a Markovian pump, by effectively breaking a symmetry of the unstable, linearized dynamics. We analyze two concrete examples of this mechanism. The first is a new kind of $\mathcal{PT}$ laser, where Hermitian Hamiltonian interactions can move the dynamics between the $\mathcal{PT}$ broken and unbroken phases and thus induce stability. The second uses onsite Kerr or Hubbard type interactions to break the chiral symmetry in a topological photonic lattice, inducing exotic phenomena from topological lasing to the stabilization of Fock states in a topologically protected edge mode.

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Andrew Pocklington, Aashish A. Clerk. 2023-07-31. Stability via symmetry breaking in interacting driven systems. https://doi.org/10.1103/physrevb.109.054309

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