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Title: Effect of fluctuations on the NMR relaxation beyond the Abrikosov vortex state

Abstract

Here, the effect of fluctuations on the nuclear magnetic resonance (NMR) relaxation rate W = T–11 is studied in a complete phase diagram of a two-dimensional superconductor above the upper critical field line Hc2(T). In the region of relatively high temperatures and low magnetic fields, the relaxation rate W is determined by two competing effects. The first one is its decrease in the result of suppression of the quasiparticle density of states (DOS) due to formation of fluctuation Cooper pairs (FCPs). The second one is a specific, purely quantum relaxation process of the Maki-Thompson (MT) type, which for low field leads to an increase of the relaxation rate. The latter describes particular fluctuation processes involving self-pairing of a single electron on self-intersecting trajectories of a size up to phase-breaking length ℓΦ which becomes possible due to an electron spin-flip scattering event at a nucleus. As a result, different scenarios with either growth or decrease of the NMR relaxation rate are possible upon approaching the normal-metal–type-II superconductor transition. The character of fluctuations changes along the line Hc2(T) from the thermal long-wavelength type in weak magnetic fields to the clusters of rotating FCPs in fields comparable to Hc2(0). We find that belowmore » the well-defined temperature T*0 ≈ 0.6Tc0, the MT process becomes ineffective even in the absence of intrinsic pair breaking. The small scale of the FCP rotations ξxy in such high fields impedes formation of long (≲ℓΦ) self-intersecting trajectories, causing the corresponding relaxation mechanism to lose its efficiency. This reduces the effect of superconducting fluctuations in the domain of high fields and low temperatures to just the suppression of quasiparticle DOS, analogous to the Abrikosov vortex phase below the Hc2(T) line.« less

Authors:
 [1];  [2];  [3]
  1. Argonne National Lab. (ANL), Argonne, IL (United States); Northern Illinois Univ., DeKalb, IL (United States)
  2. Argonne National Lab. (ANL), Argonne, IL (United States)
  3. Argonne National Lab. (ANL), Argonne, IL (United States); CNR-SPIN, Rome (Italy)
Publication Date:
Research Org.:
Argonne National Laboratory (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
OSTI Identifier:
1356371
Alternate Identifier(s):
OSTI ID: 1212956
Grant/Contract Number:  
AC02-06CH11357
Resource Type:
Accepted Manuscript
Journal Name:
Physical Review. B, Condensed Matter and Materials Physics
Additional Journal Information:
Journal Volume: 92; Journal Issue: 5; Journal ID: ISSN 1098-0121
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

Citation Formats

Glatz, A., Galda, A., and Varlamov, A. A. Effect of fluctuations on the NMR relaxation beyond the Abrikosov vortex state. United States: N. p., 2015. Web. doi:10.1103/PhysRevB.92.054513.
Glatz, A., Galda, A., & Varlamov, A. A. Effect of fluctuations on the NMR relaxation beyond the Abrikosov vortex state. United States. https://doi.org/10.1103/PhysRevB.92.054513
Glatz, A., Galda, A., and Varlamov, A. A. Tue . "Effect of fluctuations on the NMR relaxation beyond the Abrikosov vortex state". United States. https://doi.org/10.1103/PhysRevB.92.054513. https://www.osti.gov/servlets/purl/1356371.
@article{osti_1356371,
title = {Effect of fluctuations on the NMR relaxation beyond the Abrikosov vortex state},
author = {Glatz, A. and Galda, A. and Varlamov, A. A.},
abstractNote = {Here, the effect of fluctuations on the nuclear magnetic resonance (NMR) relaxation rate W = T–11 is studied in a complete phase diagram of a two-dimensional superconductor above the upper critical field line Hc2(T). In the region of relatively high temperatures and low magnetic fields, the relaxation rate W is determined by two competing effects. The first one is its decrease in the result of suppression of the quasiparticle density of states (DOS) due to formation of fluctuation Cooper pairs (FCPs). The second one is a specific, purely quantum relaxation process of the Maki-Thompson (MT) type, which for low field leads to an increase of the relaxation rate. The latter describes particular fluctuation processes involving self-pairing of a single electron on self-intersecting trajectories of a size up to phase-breaking length ℓΦ which becomes possible due to an electron spin-flip scattering event at a nucleus. As a result, different scenarios with either growth or decrease of the NMR relaxation rate are possible upon approaching the normal-metal–type-II superconductor transition. The character of fluctuations changes along the line Hc2(T) from the thermal long-wavelength type in weak magnetic fields to the clusters of rotating FCPs in fields comparable to Hc2(0). We find that below the well-defined temperature T*0 ≈ 0.6Tc0, the MT process becomes ineffective even in the absence of intrinsic pair breaking. The small scale of the FCP rotations ξxy in such high fields impedes formation of long (≲ℓΦ) self-intersecting trajectories, causing the corresponding relaxation mechanism to lose its efficiency. This reduces the effect of superconducting fluctuations in the domain of high fields and low temperatures to just the suppression of quasiparticle DOS, analogous to the Abrikosov vortex phase below the Hc2(T) line.},
doi = {10.1103/PhysRevB.92.054513},
journal = {Physical Review. B, Condensed Matter and Materials Physics},
number = 5,
volume = 92,
place = {United States},
year = {Tue Aug 25 00:00:00 EDT 2015},
month = {Tue Aug 25 00:00:00 EDT 2015}
}

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Works referenced in this record:

Principles of Magnetic Resonance
book, January 1990


Basic aspects and main results of NMR-NQR spectroscopies in high-temperature superconductors
journal, October 1998


Flux-line dynamics in YBa 2 Cu 4 O 8 from Y 89 NMR
journal, October 1996


Quantum fluctuations and dynamic clustering of fluctuating Cooper pairs
journal, May 2011


On the low-energy excitations in superconducting YNi 2 B 2 C from B 11 NMR relaxation around the critical field
journal, June 2005


Superconducting fluctuation effects on the local electronic spin susceptibility. II. The impure case
journal, July 1977


Effects of Superconducting Fluctuations on NMR Relaxation Rate
journal, February 1989

  • Kuboki, Kazuhiro; Fukuyama, Hidetoshi
  • Journal of the Physical Society of Japan, Vol. 58, Issue 2
  • DOI: 10.1143/JPSJ.58.376

Effects of superconducting fluctuations on the NMR relaxation rateT 1 ?1 of two-dimensional systems aboveT c
journal, December 1992

  • Heym, J�rgen
  • Journal of Low Temperature Physics, Vol. 89, Issue 5-6
  • DOI: 10.1007/BF00683891

Effect of superconducting fluctuations on spin susceptibility and NMR relaxation rate
journal, October 1994


Effects of strong magnetic fields on pairing fluctuations in high-temperature superconductors
journal, May 1999


Magnetic field dependence of the superconducting fluctuation contribution to NMR-NQR relaxation
journal, July 2000

  • Mosconi, P.; Rigamonti, A.; Varlamov, A. A.
  • Applied Magnetic Resonance, Vol. 19, Issue 3-4
  • DOI: 10.1007/BF03162376

Superconducting Fluctuation Effects on the Spin-Lattice Relaxation Rate in YBa 2 Cu 3 O 6.95
journal, March 1999


Magnetic Field Independence of the Spin Gap in YBa 2 Cu 3 O 7 δ
journal, January 1999


Pseudogap in YBa 2 Cu 3 O 7 δ from NMR in high magnetic fields
journal, June 2002


Investigation of Fluctuating Diamagnetism and Spin Dynamics in SmFeAsO<sub>1-x</sub>F<sub>x</sub> Superconductors
journal, October 2010


Effect of Fluctuations on Electronic Properties above the Superconducting Transition
journal, January 1970

  • Abrahams, Elihu; Redi, Martha; Woo, James W. F.
  • Physical Review B, Vol. 1, Issue 1
  • DOI: 10.1103/PhysRevB.1.208

Superconductive fluctuations in the density of states and tunneling resistance in high- T c superconductors
journal, December 1990


Fluctuation spectroscopy of disordered two-dimensional superconductors
journal, September 2011


Fluctuation conductivity in intercalated superconductors
journal, January 1980

  • Aslamasov, L. G.; Varlamov, A. A.
  • Journal of Low Temperature Physics, Vol. 38-38, Issue 1-2
  • DOI: 10.1007/BF00115277

Works referencing / citing this record:

Fluctuation spectroscopy: From Rayleigh-Jeans waves to Abrikosov vortex clusters
journal, March 2018