Transport properties of quasi-one dimensional magnetically doped quantum wires

Florian Stäbler

12.12.2019 at 12:00 

Abstract: Magnetically doped quantum wires, theoretically modeled by a dense, one dimensional Kondo chain, are promising candidates to host protected transport carried by helical states. The hallmark of these helical state is the lock-in relation between spin and momentum, which leads to prominent properties, such as ballistic transport up to parametrically large length scales [1–4]. Helical states can also be used as a spin filter. This makes them highly promising for future nanoelectronic or spintronic devices. However, fabricating purely one dimensional systems is a highly non-trivial task. In this talk I will answer the question if strict one dimensionality is a requirement for the emergence of a helical phase. We used analytical methods to go beyond the simplest paradigm of a one dimensional chain and analyze two Kondo chains coupled via an interchain hopping. We identified three relevant regimes, characterized by different interchain tunneling strengths and analyzed the weak, intermediate and strong tunneling regime. [1] A. M. Tsvelik and O. M. Yevtushenko. Quantum Phase Transition and Protected Ideal Transport in a Kondo Chain. Phys. Rev. Lett., 115, 21 216402. (2015). [2] A. M. Tsvelik and O. M. Yevtushenko. Physics of arbitrarily doped Kondo lattices: From a commensurate insulator to a heavy Luttinger liquid and protected helical metal. Phys. Rev. B, 100, 16 165110. (2019). [3] A. Tsvelik and O. Yevtushenko. Helicity-protected Transport in Magnetically Doped One-Dimensional Wires. preprint, arXiv:1902.01787. (2019). [4] D. Schimmel et al. Low energy properties of the Kondo chain in the RKKY regime. New J. Phys., 18, 053004. (2016).