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Anomalous quantized conductance in a half-metal/topological superconductor/half-metal junction
1Department of Physics, Southeast University, Nanjing 210096, People's Republic of China.
Summary
Researchers discovered an anomalous quantized conductance peak in composite topological superconductors, offering a new method for detecting Majorana fermions (MFs). This finding arises from Majorana fermion-assisted Andreev reflection, even with suppressed s-wave pairing.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Phenomena
Background:
- Composite topological superconductors (TS) integrate spin-orbit coupled nanowires with s-wave superconductors.
- These materials exhibit a mix of p-wave and suppressed s-wave pairing, deviating from pure p-wave superconductivity.
Purpose of the Study:
- To investigate the pairing states and spin texture in composite topological superconductors.
- To explore the potential for detecting Majorana fermions (MFs) through conductance spectrum analysis.
Main Methods:
- Calculation of the conductance spectrum for a half-metal/TS/half-metal junction.
- Analysis of pairing states and spin texture under varying magnetic alignment.
Main Results:
- A regular quantized conductance peak associated with Majorana fermions (MFs) was observed when magnetization is parallel to MF spin.
- An anomalous quantized conductance peak emerged when magnetization is nearly antiparallel to MF spin.
- This anomalous peak is attributed to MF-assisted local Andreev reflection facilitating s-wave pairing condensation.
Conclusions:
- The study confirms the existence of anomalous quantized conductance in composite topological superconductors.
- This phenomenon, linked to nonzero s-wave pairing in a p-wave model, offers a novel approach for Majorana fermion detection.
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