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Updated: Aug 19, 2025
11:33
All-electronic Nanosecond-resolved Scanning Tunneling Microscopy: Facilitating the Investigation of Single Dopant Charge Dynamics
Published on: January 19, 2018
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Local and Nonlocal Two-Electron Tunneling Processes in a Cooper Pair Splitter
Antti Ranni1, Elsa T Mannila2, Axel Eriksson1
1NanoLund and Solid State Physics, Lund University, Box 118, 22100 Lund, Sweden.
Physical Review Letters
|December 3, 2022
Summary
We measured rates for Andreev and cotunneling processes. Cooper pair splitting via nonlocal Andreev processes showed similar coupling to elastic cotunneling, unlike stronger local Andreev processes.
Area of Science:
- Condensed Matter Physics
- Quantum Transport
Background:
- Understanding electron transport in superconductors is crucial for quantum technologies.
- Andreev and cotunneling processes govern charge transport at superconductor-normal metal interfaces.
Purpose of the Study:
- To quantify and compare the coupling coefficients of local Andreev, nonlocal Andreev, and elastic cotunneling processes.
- To investigate the underlying physics responsible for differences in coupling strengths.
Main Methods:
- Experimental measurement of transport rates and coupling coefficients.
- Theoretical modeling to explain observed phenomena.
Main Results:
- Nonlocal Andreev processes (Cooper pair splitting) share coupling coefficients with elastic cotunneling.
- Local Andreev processes are over two orders of magnitude stronger than nonlocal Andreev processes.
- Theoretical estimates align with experimental findings, explaining coupling differences.
Conclusions:
- The significant difference in local versus nonlocal coupling arises from competing electron diffusion in the superconductor and tunnel junction transparency.
- These findings provide insights into controlling quantum phenomena at interfaces.
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