Scalar Spin Chirality from Dissipative Pumping and Lamb Shift Precession

Abstract:Circulating currents in triangular triple quantum dots reverse repeatedly with bias even at zero magnetic flux and for a real Hamiltonian, a phenomenon whose origin has remained unclear. We show that dissipative tunneling prepares an orbital pseudospin, while virtual charge fluctuations generate a noncollinear Lamb field that rotates it toward the chiral direction. Bias changes their relative orientation and thereby reverses the current. This reservoir-induced orbital Hanle effect converts a nonchiral orbital polarization into scalar spin chirality, which an exact ground-multiplet identity links to the circulating current. Hierarchical-equations-of-motion calculations show that the low-bias reversal survives beyond the second-order weak-coupling description, while the quadratic growth of chirality after a sudden voltage switch identifies precession. More broadly, time-reversal-odd responses can emerge in open quantum systems from the interplay between dissipative state preparation and coherent precession.

Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Quantum Physics (quant-ph)

arXiv:2608.30324 [cond-mat.mes-hall]

(or arXiv:2608.30324v1 [cond-mat.mes-hall] for this version)

https://doi.org/10.48550/arXiv.2608.30324 Focus to learn more arXiv-issued DOI via DataCite (pending registration)

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