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arXiv · 1201.3080

Coherent control of correlated nanodevices: A hybrid time-dependent numerical renormalization-group approach to periodic switching

Eitan Eidelstein·Avraham Schiller·Fabian Guettge·Frithjof B. Anders
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Abstract

The time-dependent numerical renormalization-group approach (TD-NRG), originally devised for tracking the real-time dynamics of quantum-impurity systems following a single quantum quench, is extended to multiple switching events. This generalization of the TD-NRG encompasses the possibility of periodic switching, allowing for coherent control of strongly correlated systems by an external time-dependent field. To this end, we have embedded the TD-NRG in a hybrid framework that combines the outstanding capabilities of the numerical renormalization group to systematically construct the effective low-energy Hamiltonian of the system with the prowess of complementary approaches for calculating the real-time dynamics derived from this Hamiltonian. We demonstrate the power of our approach by hybridizing the TD-NRG with the Chebyshev expansion technique in order to investigate periodic switching in the interacting resonant-level model. Although the interacting model shares the same low-energy fixed point as its noninteracting counterpart, we surprisingly find the gradual emergence of damped oscillations as the interaction strength is increased. Focusing on a single quantum quench and using a strong-coupling analysis, we reveal the origin of these interaction-induced oscillations and provide an analytical estimate for their frequency. The latter agrees well with the numerical results.

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Eitan Eidelstein, Avraham Schiller, Fabian Guettge, Frithjof B. Anders. 2012-01-15. Coherent control of correlated nanodevices: A hybrid time-dependent numerical renormalization-group approach to periodic switching. https://doi.org/10.1103/physrevb.85.075118

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