We shall revisit the conventional adiabatic or Markov approximation, stressing its intrinsic failure in describing the proper quantum-mechanical evolution of a generic subsystem interacting with its environment. In particular, we shall show that - contrary to the semiclassical case - the Markov limit does not preserve the positivedefinite character of the corresponding density matrix, thus leading to highly non-physical results. To overcome this problem, we shall propose an alternative adiabatic procedure which (i) in the semiclassical limit reduces to the standard Fermi's golden rule, and (ii) describes a genuine Limblad evolution, thus providing a reliable/robust treatment of energy-dissipation and dephasing processes in electronic quantum devices. Compared to standard master-equation formulations, the proposed approach does not involve/require any reduction or average procedure, exactly as for the derivation of the well known Fermi's golden rule.
Quantum Fermi's golden rule for semiconductor nanodevices / Rossi, Fausto. - In: PHYSICA STATUS SOLIDI. C, CURRENT TOPICS IN SOLID STATE PHYSICS. - ISSN 1862-6351. - STAMPA. - 5:1(2008), pp. 35-38. [10.1002/pssc.200776506]
Quantum Fermi's golden rule for semiconductor nanodevices
ROSSI, FAUSTO
2008
Abstract
We shall revisit the conventional adiabatic or Markov approximation, stressing its intrinsic failure in describing the proper quantum-mechanical evolution of a generic subsystem interacting with its environment. In particular, we shall show that - contrary to the semiclassical case - the Markov limit does not preserve the positivedefinite character of the corresponding density matrix, thus leading to highly non-physical results. To overcome this problem, we shall propose an alternative adiabatic procedure which (i) in the semiclassical limit reduces to the standard Fermi's golden rule, and (ii) describes a genuine Limblad evolution, thus providing a reliable/robust treatment of energy-dissipation and dephasing processes in electronic quantum devices. Compared to standard master-equation formulations, the proposed approach does not involve/require any reduction or average procedure, exactly as for the derivation of the well known Fermi's golden rule.Pubblicazioni consigliate
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https://hdl.handle.net/11583/1797132
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