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Spin-selective transport in a correlated double quantum dot-Majorana wire system
Piotr Majek1, Ireneusz Weymann2
1Institute of Spintronics and Quantum Information, Faculty of Physics, Adam Mickiewicz University, ul. Uniwersytetu Poznańskiego 2, 61-614, Poznań, Poland. pmajek@amu.edu.pl.
Scientific Reports
|July 31, 2024
Summary
This study explores spin-dependent transport in quantum dots connected to topological superconductors and ferromagnetic materials. It reveals how Majorana modes and Kondo effects influence spin polarization, leading to unique transport signatures.
Area of Science:
- Condensed Matter Physics
- Quantum Information Science
- Spintronics
Background:
- Investigating spin-dependent transport in complex quantum systems is crucial for advancing quantum technologies.
- Majorana zero-energy modes in topological superconductors offer potential for fault-tolerant quantum computing.
- The interplay between Kondo effect and ferromagnetic interactions in quantum dots presents unique transport phenomena.
Purpose of the Study:
- To analyze spin-dependent transport through a double quantum dot coupled to a topological superconducting nanowire and ferromagnetic leads.
- To understand the competition between Majorana mode leakage, Kondo effect, and exchange fields.
- To reveal unique transport signatures arising from the interplay of these phenomena.
Main Methods:
- Numerical Renormalization Group (NRG) method for spectral properties and temperature-dependent conductance.
- Analysis of spin-resolved linear conductance.
- Investigation of systems with Majorana zero-energy modes and ferromagnetic contacts.
Main Results:
- Observed unique signatures of interplay between spin-resolved tunneling, Kondo effect, and Majorana modes.
- Uncovered competing coupling between topological superconductor and ferromagnetic leads.
- Demonstrated perfect conductance spin polarization via conductance quenching in one spin channel.
- Showed that conductance spin polarization sign can be tuned by spin imbalance and topological wire interaction strength.
Conclusions:
- Even minimal spin polarization in tunneling significantly impacts transport properties.
- The system exhibits a competing character between topological superconductor coupling and ferromagnetic leads.
- Unique transport characteristics signal the presence and influence of Majorana modes and Kondo effect.
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