SAMOP 2023 – wissenschaftliches Programm

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A: Fachverband Atomphysik

A 16: Molecules in Intense Fields and Quantum Control (joint session MO/A)

A 16.5: Vortrag

Mittwoch, 8. März 2023, 15:45–16:00, F102

Strong coupling to a phonon bath enhances adiabatic population transfer — •Frank Grossmann and Michael Werther — Technische Universität Dresden, Institut für Theoretische Physik, 01062 Dresden

We present a study on the influence of an environmental heat bath on the rapid adiabatic passage scheme for optimal population transfer in a two-level system, originally invented in nuclear magnetic resonance [1].

To cope with strong coupling to an external phonon bath with superohmic spectral density, we are solving the time-dependent Schrödinger equation of the extended system, including a carefully chosen finite number of bath modes, using the multi-Davydov D2-Ansatz [2], which will be briefly reviewed. This Ansatz allows for the treatment of the non-Markovian reduced dynamics of the two-level subsystem. We find that strong system-bath coupling stabilizes the transition probability from the lower to the upper level as a function of the area under the laser pulse. This dissipative engineering effect could only be uncovered by a non-Markovian treatment. For strong coupling, the transition probability then becomes a monotonically increasing function of the pulse area at zero temperature of the heat bath. Finite temperatures break the monotonicity in the range of pulse areas that we studied but not the stability of the observed effect.

[1] M. Werther and F. Grossmann, Phys. Rev. A 102, 063710 (2020)

[2] M. Werther and F. Grossmann, Phys. Rev. B 101, 174315 (2020)