Details
| Original language | English |
|---|---|
| Article number | 164005 |
| Journal | Journal of Physics Condensed Matter |
| Volume | 34 |
| Issue number | 16 |
| Publication status | Published - 23 Feb 2022 |
| Externally published | Yes |
Abstract
Topological Josephson junctions (TJJs) have been a subject of widespread interest due to their hosting of Majorana zero modes. In long junctions, i.e. junctions where the junction length exceeds the superconducting coherence length, TJJs manifest themselves in specific features of the critical current (Beenakker 2013 Phys. Rev. Lett. 110 017003). Here we propose to couple the helical edge states mediating the TJJ to additional channels or quantum dots, by which the effective junction length can be increased by tunable parameters associated with these couplings, so that such measurements become possible even in short junctions. Besides effective low-energy models that we treat analytically, we investigate realizations by a Kane-Mele model with edge passivation and treat them numerically via tight binding models. In each case, we explicitly calculate the critical current using the Andreev bound state spectrum and show that it differs in effectively long junctions in the cases of strong and weak parity changing perturbations (quasiparticle poisoning).
Keywords
- Andreev bound states, fractional Josephson junctions, Majorana modes, quasiparticle poisoning, topological insulators
ASJC Scopus subject areas
- Materials Science(all)
- General Materials Science
- Physics and Astronomy(all)
- Condensed Matter Physics
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In: Journal of Physics Condensed Matter, Vol. 34, No. 16, 164005, 23.02.2022.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Tunable effective length of fractional Josephson junctions
AU - Frombach, Daniel
AU - Recher, Patrik
N1 - Funding Information: We acknowledge useful discussions with F Dominguez and financial support by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) within the framework of Germany’s Excellence Strategy-EXC-2123 QuantumFrontiers-390837967.
PY - 2022/2/23
Y1 - 2022/2/23
N2 - Topological Josephson junctions (TJJs) have been a subject of widespread interest due to their hosting of Majorana zero modes. In long junctions, i.e. junctions where the junction length exceeds the superconducting coherence length, TJJs manifest themselves in specific features of the critical current (Beenakker 2013 Phys. Rev. Lett. 110 017003). Here we propose to couple the helical edge states mediating the TJJ to additional channels or quantum dots, by which the effective junction length can be increased by tunable parameters associated with these couplings, so that such measurements become possible even in short junctions. Besides effective low-energy models that we treat analytically, we investigate realizations by a Kane-Mele model with edge passivation and treat them numerically via tight binding models. In each case, we explicitly calculate the critical current using the Andreev bound state spectrum and show that it differs in effectively long junctions in the cases of strong and weak parity changing perturbations (quasiparticle poisoning).
AB - Topological Josephson junctions (TJJs) have been a subject of widespread interest due to their hosting of Majorana zero modes. In long junctions, i.e. junctions where the junction length exceeds the superconducting coherence length, TJJs manifest themselves in specific features of the critical current (Beenakker 2013 Phys. Rev. Lett. 110 017003). Here we propose to couple the helical edge states mediating the TJJ to additional channels or quantum dots, by which the effective junction length can be increased by tunable parameters associated with these couplings, so that such measurements become possible even in short junctions. Besides effective low-energy models that we treat analytically, we investigate realizations by a Kane-Mele model with edge passivation and treat them numerically via tight binding models. In each case, we explicitly calculate the critical current using the Andreev bound state spectrum and show that it differs in effectively long junctions in the cases of strong and weak parity changing perturbations (quasiparticle poisoning).
KW - Andreev bound states
KW - fractional Josephson junctions
KW - Majorana modes
KW - quasiparticle poisoning
KW - topological insulators
UR - http://www.scopus.com/inward/record.url?scp=85125553901&partnerID=8YFLogxK
U2 - 10.1088/1361-648X/ac4dbc
DO - 10.1088/1361-648X/ac4dbc
M3 - Article
C2 - 35062004
AN - SCOPUS:85125553901
VL - 34
JO - Journal of Physics Condensed Matter
JF - Journal of Physics Condensed Matter
SN - 0953-8984
IS - 16
M1 - 164005
ER -