Fate of entanglement in open quantum spin liquid: Time evolution of its genuinemultipartite negativity upon sudden coupling to a dissipative bosonic environment

Topological properties of many-body entanglement in quantum spin liquids (QSLs), persisting at

arbitrarily long distances, have been intensely explored over the past two decades, but mostly for

QSLs viewed as closed quantum systems. However, in experiments and potential quantum computing

applications, candidate materials for this exotic phase of quantum matter will always interact with

a dissipative environment, such as the one generated by bosonic quasiparticles in solids at finite

temperature. Here we investigate the spatial distribution of entanglement and its stability for the

Kitaev model of QSL made open by sudden coupling to an infinite bosonic bath of Caldeira-Leggett

type and time-evolved using the Lindblad quantum master equation in the Markovian regime (i.e., for

weak coupling) or tensor network methods for open quantum systems in the non-Markovian regime

(i.e., for strong coupling). From the time-evolved density matrix of QSL and its subregions, we

extract genuine multipartite negativity (GMN), quantum Fisher information, spin-spin correlators,

and expectation value (EV) of the Wilson loop operator. In particular, time-dependence of GMN

offers the most penetrating insights: (i) in the Markovian regime, it remains non-zero in larger

loopy subregions of QSL (as also discovered very recently for closed QSLs) up to temperatures

comparable to Kitaev exchange interaction at which other quantities, such as EV of the Wilson loop

operator, vanish; (ii) in the non-Markovian regime with pronounced memory effects, GMN remains

non-zero up to even higher temperatures, while also acquiring non-zero value in smaller non-loopy

subregions. The non-Markovian dynamics can also generate emergent interactions between spins,

thereby opening avenues for tailoring properties of QSL via engineering of dissipation.