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Updated: May 14, 2026
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Published on: September 2, 2016
Negative spinΔTnoise induced by spin-flip scattering and Andreev reflection
Sachiraj Mishra1,2, Colin Benjamin1,2
1School of Physical Sciences, National Institute of Science Education and Research, HBNI, Jatni 752050, India.
Summary
Spin noise in superconducting junctions can become negative, unlike charge noise. This sign reversal reveals unique spin-dependent scattering mechanisms, distinguishing it from quantum shot noise.
Area of Science:
- Condensed Matter Physics
- Quantum Phenomena
- Spintronics
Background:
- Understanding noise in electronic transport is crucial for quantum device development.
- Superconducting hybrid junctions offer a platform to study complex quantum correlations.
Purpose of the Study:
- To investigate charge and spin noise in normal metal-spin flipper-normal metal-insulator-superconductor (N-sf-N-I-S) junctions.
- To analyze the conditions leading to sign reversal in spin noise and its implications.
Main Methods:
- Theoretical analysis of charge and spin noise in N-sf-N-I-S junctions.
- Examination of the interplay between spin-flip scattering and Andreev reflection.
Main Results:
- Charge noise is always positive, while spin noise can reverse sign from positive to negative.
- Negative spin noise arises from opposite-spin correlations, distinct from same-spin correlations in quantum shot noise.
- This sign reversal provides insights into scattering mechanisms not detectable by quantum shot noise alone.
Conclusions:
- Negative spin noise acts as a unique probe for cooperative effects of Andreev reflection and spin flipping.
- The findings highlight the role of spin-dependent scattering in superconducting hybrid devices.
- This work offers new perspectives on noise mechanisms and their fingerprints in quantum systems.
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