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arXiv · 2104.02568

Spin-orbit enabled quantum transport channels in a two-hole double quantum dot

Alex Bogan·Sergei Studenikin·Marek Korkusinski·Louis Gaudreau·Jason Phoenix·Piotr Zawadzki·Andy Sachrajda·Lisa Tracy·John Reno·Terry Hargett
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Abstract

We analyze experimentally and theoretically the transport spectra of a gated lateral GaAs double quantum dot containing two holes. The strong spin-orbit interaction present in the hole subband lifts the Pauli spin blockade and allows to map out the complete spectra of the two-hole system. By performing measurements in both source-drain voltage directions, at different detunings and magnetic fields, we carry out quantitative fitting to a Hubbard two-site model accounting for the tunnel coupling to the leads and the spin-flip relaxation process. We extract the singlet-triplet gap and the magnetic field corresponding to the singlet-triplet transition in the double-hole ground state. Additionally, at the singlet-triplet transition we find a resonant enhancement (in the blockaded direction) and suppression of current (in the conduction direction). The current enhancement stems from the multiple resonance of two-hole levels, opening several conduction channels at once. The current suppression arises from the quantum interference of spin-conserving and spin flipping tunneling processes.

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Alex Bogan, Sergei Studenikin, Marek Korkusinski, Louis Gaudreau, Jason Phoenix, Piotr Zawadzki, Andy Sachrajda, Lisa Tracy, John Reno, Terry Hargett. 2021-04-06. Spin-orbit enabled quantum transport channels in a two-hole double quantum dot. https://doi.org/10.1103/physrevb.103.235310

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