Probing Majorana localization in minimal Kitaev chains through a quantum dot
(2023) In Physical Review Research 5(4).- Abstract
Artificial Kitaev chains, formed by quantum dots coupled via superconductors, have emerged as a promising platform for realizing Majorana bound states. Even a minimal Kitaev chain (a quantum dot-superconductor-quantum dot setup) can host Majorana states at discrete sweet spots. However, unambiguously identifying Majorana sweet spots in such a system is still challenging. In this work, we propose an additional dot coupled to one side of the chain as a tool to identify good sweet spots in minimal Kitaev chains. When the two Majorana states in the chain overlap, the extra dot couples to both and thus splits an even-odd ground-state degeneracy when its level is on resonance. In contrast, a ground-state degeneracy will persist for... (More)
Artificial Kitaev chains, formed by quantum dots coupled via superconductors, have emerged as a promising platform for realizing Majorana bound states. Even a minimal Kitaev chain (a quantum dot-superconductor-quantum dot setup) can host Majorana states at discrete sweet spots. However, unambiguously identifying Majorana sweet spots in such a system is still challenging. In this work, we propose an additional dot coupled to one side of the chain as a tool to identify good sweet spots in minimal Kitaev chains. When the two Majorana states in the chain overlap, the extra dot couples to both and thus splits an even-odd ground-state degeneracy when its level is on resonance. In contrast, a ground-state degeneracy will persist for well-separated Majorana states. This difference can be used to identify points in parameter space with spatially separated Majorana states, using tunneling spectroscopy measurements. We perform a systematic analysis of different relevant situations. We show that the additional dot can help distinguish between Majorana sweet spots and other trivial zero-energy crossings. We also characterize the different conductance patterns, which can serve as a guide for future experiments aiming to study Majorana states in minimal Kitaev chains.
(Less)
- author
- Souto, Rubén Seoane LU ; Tsintzis, Athanasios LU ; Leijnse, Martin LU and Danon, Jeroen
- organization
- publishing date
- 2023-10
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Physical Review Research
- volume
- 5
- issue
- 4
- article number
- 043182
- publisher
- American Physical Society
- external identifiers
-
- scopus:85179006863
- ISSN
- 2643-1564
- DOI
- 10.1103/PhysRevResearch.5.043182
- language
- English
- LU publication?
- yes
- id
- 4b14a99b-470e-4225-a743-63b1d3cbc37b
- date added to LUP
- 2024-01-09 11:09:29
- date last changed
- 2024-01-09 11:09:29
@article{4b14a99b-470e-4225-a743-63b1d3cbc37b, abstract = {{<p>Artificial Kitaev chains, formed by quantum dots coupled via superconductors, have emerged as a promising platform for realizing Majorana bound states. Even a minimal Kitaev chain (a quantum dot-superconductor-quantum dot setup) can host Majorana states at discrete sweet spots. However, unambiguously identifying Majorana sweet spots in such a system is still challenging. In this work, we propose an additional dot coupled to one side of the chain as a tool to identify good sweet spots in minimal Kitaev chains. When the two Majorana states in the chain overlap, the extra dot couples to both and thus splits an even-odd ground-state degeneracy when its level is on resonance. In contrast, a ground-state degeneracy will persist for well-separated Majorana states. This difference can be used to identify points in parameter space with spatially separated Majorana states, using tunneling spectroscopy measurements. We perform a systematic analysis of different relevant situations. We show that the additional dot can help distinguish between Majorana sweet spots and other trivial zero-energy crossings. We also characterize the different conductance patterns, which can serve as a guide for future experiments aiming to study Majorana states in minimal Kitaev chains.</p>}}, author = {{Souto, Rubén Seoane and Tsintzis, Athanasios and Leijnse, Martin and Danon, Jeroen}}, issn = {{2643-1564}}, language = {{eng}}, number = {{4}}, publisher = {{American Physical Society}}, series = {{Physical Review Research}}, title = {{Probing Majorana localization in minimal Kitaev chains through a quantum dot}}, url = {{http://dx.doi.org/10.1103/PhysRevResearch.5.043182}}, doi = {{10.1103/PhysRevResearch.5.043182}}, volume = {{5}}, year = {{2023}}, }