Hidden non-Markovianity in open quantum systems

Quantum regression beyond the Born-Markov approximation for generalized spin-boson models

“…[54]. We stress that no other choice of coupling would yield exact semigroup dynamics at all times, the correspondence between f (ω) and a(t) being one-to-one; however, relaxing our request by asking the semigroup property to only hold in a finite time window, one would have infinitely many other choices [55,56]. Also notice that, as a straightforward consequence of the Paley-Wiener theorem, relaxing our request by asking for semigroup dynamics at t → ∞ would still require the energy spectrum of the boson field to be unbounded from below.…”

Solvable class of non-Markovian quantum multipartite dynamics

“…For tackling this issue a broad class of phenomenological and theoretical approaches has been formulated [3], dealing with both time-convoluted and convolutionless master equations [11]. Examples include the dynamics induced by stochastic Hamiltonians defined by non-white noises [12], phenomenological single memory kernels [13][14][15][16], interaction with incoherent degrees of freedom [17][18][19][20][21][22] and arbitrary ancilla systems [23,24], related quantum collisional models [25][26][27][28][29][30][31][32], quantum generalizations of semi-Markov processes [33,34], and random (convex) superpositions of unitary and unital maps [35][36][37], together with some exact derivations from underlying (microscopic or effective) unitary dynamics [38][39][40][41][42][43][44][45][46].…”

Memory Effects in Quantum Dynamics Modelled by Quantum Renewal Processes

“…In particular, strategies aimed at controlling the non-Markovianity of the dynamics explored the manipulation of system–environmental coupling [ 15 , 16 , 17 ], or modification of the reduced system itself [ 18 , 19 ]. The possibility of delaying the occurrence of non-Markovianity [ 20 ] and enhancing it by means of feedback control [ 21 ] was also investigated.…”