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Mapping the Topological Proximity-Induced Gap in Multiterminal Josephson Junctions
M Wisne1, Y Deng1, I M A Lilja2
1Department of Physics and Astronomy, <a href="https://ror.org/000e0be47">Northwestern University</a>, 2145 Sheridan Road, Evanston, Illinois 60208, USA.
Physical Review Letters
|January 3, 2025
Summary
Researchers explored multiterminal Josephson junctions (MTJJs) as topological crystals. Measuring MTJJ resistance revealed topological modulations in quasiparticle density of states, offering a new technique for studying topological physics.
Area of Science:
- Condensed Matter Physics
- Quantum Materials
- Superconductivity
Background:
- Multitermerminal Josephson junctions (MTJJs) are proposed as artificial topological crystals.
- The topological properties of MTJJs are linked to modulations in the quasiparticle density of states (DOS) within the normal metal.
- These modulations are theoretically probeable via tunneling measurements.
Purpose of the Study:
- To demonstrate a practical method for revealing topological effects in MTJJs.
- To investigate the relationship between MTJJ resistance and phase differences.
- To establish a technique for probing the quasiparticle DOS modulation.
Main Methods:
- Fabrication and measurement of diffusive multiterminal Josephson junctions (MTJJs).
- Utilizing normal contacts for resistance measurements.
- Analyzing the resistance as a function of superconducting phase differences ({í_i}).
Main Results:
- Observed rich structure in the resistance of diffusive MTJJs.
- Demonstrated that resistance measurements can reveal topological modulations in the quasiparticle DOS.
- Established a correlation between resistance variations and phase differences.
Conclusions:
- Resistance measurements provide a simple and powerful technique for exploring topological effects in MTJJs.
- The study validates MTJJs as platforms for studying topological phenomena.
- The findings open avenues for further research into topological quantum devices.
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