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Nernst effect and diamagnetism in phase fluctuating superconductors
Daniel Podolsky1, Srinivas Raghu, Ashvin Vishwanath
1Department of Physics, University of California, Berkeley, California 94720, USA.
Physical Review Letters
|October 13, 2007
Summary
Superconducting systems exhibit a sharper Nernst effect decay than predicted, linked to diamagnetism. This suggests a dilute vortex liquid model explains behavior in underdoped cuprates above Tc.
Area of Science:
- Condensed matter physics
- Superconductivity research
Background:
- Superconductivity is often destroyed by phase fluctuations.
- Understanding the behavior of superconducting systems near critical temperatures is crucial.
Purpose of the Study:
- Investigate the Nernst effect in superconducting systems near the phase fluctuation regime.
- Explore the relationship between the Nernst effect, diamagnetism, and vortex dynamics.
- Interpret experimental data from underdoped cuprates.
Main Methods:
- Analysis of Nernst effect temperature decay.
- Quantitative comparison with diamagnetism measurements.
- Theoretical interpretation using a dilute vortex liquid model.
Main Results:
- Observed a sharper temperature decay of the Nernst effect than predicted by Gaussian fluctuations.
- Found the Nernst effect onset temperature tracks the critical temperature (Tc), not the pairing temperature.
- Established a quantitative link between magnetization and transverse thermoelectric conductivity.
- Interpreted underdoped cuprate data using a dilute vortex liquid model above Tc.
Conclusions:
- Phase fluctuations significantly impact the Nernst effect in superconductors.
- The dilute vortex liquid model provides a viable explanation for observed phenomena in underdoped cuprates.
- The interplay between Nernst effect and diamagnetism offers insights into superconducting states.
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