Abstract
Coupling with an external environment inevitably affects the dynamics of a quantum system. Here, we consider how charging performances of a quantum battery, modelled as a two level system, are influenced by the presence of an Ohmic thermal reservoir. The latter is coupled to both longitudinal and transverse spin components of the quantum battery including decoherence and pure dephasing mechanisms. Charging and discharging dynamics of the quantum battery, subjected to a static driving, are obtained exploiting a proper mapping into the so-called spin-boson model. Analytic expressions for the time evolution of the energy stored in the weak coupling regime are presented relying on a systematic weak damping expansion. Here, decoherence and pure dephasing dissipative coupling are discussed in details. We argue that the former results in better charging performances, showing also interesting features reminiscent of the Lamb shift level splitting renormalization induced by the presence of the reservoir. Charging stability is also addressed, by monitoring the energy behaviour after the charging protocol has been switched off. This study presents a general framework to investigate relaxation effects, able to include also non Markovian effects, and it reveals the importance of controlling and, possibly, engineering system-bath coupling in the realization of quantum batteries.
Highlights
Quantum properties can play a predominant role in determining the behaviour of micro- and nano-devices
We use the previous results in order to describe the dynamics of the quantum batteries (QBs)
Using the expressions (29), (30) with the mapping in (22), (23) the average energies associated to the QB and to the charger C are directly expressed in terms of the time evolution of the spin components σz(t) and σx(t) of the SB model
Summary
Quantum properties can play a predominant role in determining the behaviour of micro- and nano-devices Both theoretical and experimental works considered thermodynamic aspects of small quantum systems, in the new research field called “quantum thermodynamics” [1, 2, 3, 4, 5, 6, 7, 8]. In this context one of the major issues, triggered by potential technological applications, is the possibility to efficiently store energy in small systems, exploiting quantum features, and using it on-demand providing power supply. Charging of a TLS, namely the controlled transition between the ground and the excited state, can be induced by means of an external classical drive [15, 16, 17], by properly controlling the exchange interaction between different cells [9, 18, 19], or through cell-cell coupling mediated by interaction with an external cavity radiation [23, 27, 28, 29]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
