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Multi-band quantum ratchets

M. Grifoni·M. S. Ferreira·J. Peguiron·J. B. Majer
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Abstract

We investigate directed motion in non-adiabatically rocked ratchet systems sustaining few bands below the barrier. Upon restricting the dynamics to the lowest M bands, the total system-plus-bath Hamiltonian is mapped onto a discrete tight-binding model containing all the information both on the intra- and inter-well tunneling motion. A closed form for the current in the incoherent tunneling regime is obtained. In effective single-band ratchets, no current rectification occurs. We apply our theory to describe rectification effects in vortex quantum ratchets devices. Current reversals upon variation of the ac-field amplitude or frequency are predicted.

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M. Grifoni, M. S. Ferreira, J. Peguiron, J. B. Majer. 2002-08-28. Multi-band quantum ratchets. https://doi.org/10.1103/physrevlett.89.146801

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