TY  - JOUR
PB  - SciPost Foundation
DO  - 10.21468/SciPostPhysCore.7.3.065
TI  - Flux-tunable Kitaev chain in a quantum dot array
PY  - 2024/09/18
UR  - https://scipost.org/SciPostPhysCore.7.3.065
JF  - SciPost Physics Core
JA  - SciPost Phys. Core
VL  - 7
IS  - 3
SP  - 065
A1  - Torres Luna, Juan Daniel
AU  - Bozkurt, A. Mert
AU  - Wimmer, Michael
AU  - Liu, Chun-Xiao
AB  - Connecting quantum dots through Andreev bound states in a semiconductor-superconductor hybrid provides a platform to create a Kitaev chain. Interestingly, in a double quantum dot, a pair of poor man's Majorana zero modes can emerge when the system is fine-tuned to a sweet spot, where superconducting and normal couplings are equal in magnitude. Control of the Andreev bound states is crucial for achieving this, usually implemented by varying its chemical potential. In this work, we propose using Andreev bound states in a short Josephson junction to mediate both types of couplings, with the ratio tunable by the phase difference across the junction. Now a minimal Kitaev chain can be easily tuned into the strong coupling regime by varying the phase and junction asymmetry, even without changing the dot-hybrid coupling strength. Furthermore, we identify an optimal sweet spot at $\pi$ phase, enhancing the excitation gap and robustness against phase fluctuations. Our proposal introduces a new device platform and a new tuning method for realizing quantum-dot-based Kitaev chains.
ER  -

@Article{10.21468/SciPostPhysCore.7.3.065,
	title={{Flux-tunable Kitaev chain in a quantum dot array}},
	author={Juan Daniel Torres Luna and A. Mert Bozkurt and Michael Wimmer and Chun-Xiao Liu},
	journal={SciPost Phys. Core},
	volume={7},
	pages={065},
	year={2024},
	publisher={SciPost},
	doi={10.21468/SciPostPhysCore.7.3.065},
	url={https://scipost.org/10.21468/SciPostPhysCore.7.3.065},
}