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Register a new userObservation of non-Hermitian topology with non-unitary dynamics of solid-state spins
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Non-Hermitian topological phases exhibit a number of exotic features that have no Hermitian counterparts, including the skin effect and breakdown of the conventional bulk-boundary correspondence. Here, we implement the non-Hermitian Su-Schrieffer-Heeger (SSH) Hamiltonian, which is a prototypical model for studying non-Hermitian topological phases, with a solid-state quantum simulator consisting of an electron spin and a $^{13}$C nuclear spin in a nitrogen-vacancy (NV) center in a diamond. By employing a dilation method, we realize the desired non-unitary dynamics for the electron spin and map out its spin texture in the momentum space, from which the corresponding topological invariant can be obtained directly. Our result paves the way for further exploiting and understanding the intriguing properties of non-Hermitian topological phases with solid-state spins or other quantum simulation platforms.
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We provide a general discussion of the Liouvillian spectrum for a system coupled to a non-Markovian bath using Floquet theory. This approach is suitable when the system is described by a time-convolutionless master equation with time-periodic rates. Surprisingly, the periodic nature of rates allow us to have a stroboscopic divisible dynamical map at discrete times, which we refer to as Floquet stroboscopic divisibility. We illustrate the general theory for a Schrodinger cat which is roaming inside a non-Markovian bath, and demonstrate the appearance of stroboscopic revival of the cat at later time after its death. Our theory may have profound implications in entropy production in non-equilibrium systems.
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