Signs of spin fluctuation-mediated superconductivity from magnetotransport in a cuprate superconductor
ORAL · Invited
Abstract
In the normal state of conventional BCS superconductors the linear-in-temperature resistivity is due to electron-phonon scattering, and superconductivity is due to electron pairing mediated by phonons. These two attributes of the normal and superconducting states are inextricably linked: the stronger the scattering, the higher the transition temperature Tc.
This observation has been echoed in several unconventional superconductors where there, too, a correlation is found between the linear resistivity and Tc, irrespective of the differences in the materials [1-3]. The caveat here is that these are strange metals with linear resistivity extending to low-T; the interaction that gives rise to this anomalous scattering remains an unsettled problem. Consequently, an understanding of the scattering rate and its variation with temperature and angle are crucial to resolve the underlying interactions which form the strange metal and cause superconductivity.
The quasiparticle scattering rate can be indirectly measured in magnetotransport measurements and quantified using a semi-classical Boltzmann formalism. In this talk I will present the results of in-plane magnetoresistance (MR) measurements on combinatorial thin films of the electron-doped cuprate LCCO over a wide doping range (x=0.116 to x=0.188). From a semi-classical Boltzmann transport perspective, I will explain how spin fluctuations were taken into account to explain the MR, including the incorporation of current vertex corrections to interpret the Hall effect. Finally, I will argue that the scattering rate obtained from the MR shows strong evidence for spin fluctuation-mediated superconductivity in the electron-doped cuprates.
[1] Doiron-Leryaud, PRB 80, 214531 (2009)
[2] Cooper, Science 323, 603-607 (2009)
[3] Jin, Nature 476, 73-75 (2011)
This observation has been echoed in several unconventional superconductors where there, too, a correlation is found between the linear resistivity and Tc, irrespective of the differences in the materials [1-3]. The caveat here is that these are strange metals with linear resistivity extending to low-T; the interaction that gives rise to this anomalous scattering remains an unsettled problem. Consequently, an understanding of the scattering rate and its variation with temperature and angle are crucial to resolve the underlying interactions which form the strange metal and cause superconductivity.
The quasiparticle scattering rate can be indirectly measured in magnetotransport measurements and quantified using a semi-classical Boltzmann formalism. In this talk I will present the results of in-plane magnetoresistance (MR) measurements on combinatorial thin films of the electron-doped cuprate LCCO over a wide doping range (x=0.116 to x=0.188). From a semi-classical Boltzmann transport perspective, I will explain how spin fluctuations were taken into account to explain the MR, including the incorporation of current vertex corrections to interpret the Hall effect. Finally, I will argue that the scattering rate obtained from the MR shows strong evidence for spin fluctuation-mediated superconductivity in the electron-doped cuprates.
[1] Doiron-Leryaud, PRB 80, 214531 (2009)
[2] Cooper, Science 323, 603-607 (2009)
[3] Jin, Nature 476, 73-75 (2011)
*European Research Council (ERC), Grant Agreement No. 835279- Catch-22
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Publication: C. M. Duffy et al;, Evidence for spin-fluctuation-mediated superconductivity in electron-doped cuprates arXiv:2502.13612
Presenters
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Caitlin M Duffy
- Centre National de la Recherche Scientifique
- LNCMI-T Toulouse