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TT: Fachverband Tiefe Temperaturen
TT 53: Topology: Majorana Physics
TT 53.5: Vortrag
Donnerstag, 19. März 2020, 10:30–10:45, HSZ 103
Time scales for charge-transfer based operations on Majorana systems — •Rubén Seoane Souto1,2, Karsten Flensberg2, and Martin Leijnse1,2 — 1Division of Solid State Physics and NanoLund, Lund University, Box 118, S-22100 Lund, Sweden — 2Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen, Denmark
By now, there has been a lot of evidence of the existence of Majorana fermions at the ends of topological superconductors (TSs) [1]. However, a definitive proof of their topological origin will rely on the demonstration of their non-abelian statistics, which emerge after the exchange of two or more Majorana fermions. As an alternative, they can be also demonstrated using charge-transfer based operations, where the charge of a quantum dot (QD) is transferred to two TSs [2].
In this presentation I will analyze the efficiency of charge-transfer based operations between a QD and to two TSs [3], setting bounds to the manipulation time scales. The lower bound depends on the phase difference, due to a partial decoupling of the different parity sectors. In contrast, the upper bound is determined by poisoning processes due to the tunneling of quasiparticles to the MBSs. Using realistic parameters, we find that operations can be performed with a fidelity close to unity in the ms to µs timescales, demonstrating the absence of dephasing and accumulated dynamical phases.
[1] R. Lutchyn et al., Nat. Rev. Mat. 3, 52 (2019)
[2] K. Flensberg, Phys. Rev. Lett. 106, 090503 (2011)
[3] R. Seoane Souto, K. Flensberg and M. Leijnse, arXiv:1910.08420