Ultrasonic study of La-based high-T<sub>c</sub> superconductor under high magnetic field
ORAL
Abstract
Lanthanum based cuprate superconductors are highly correlated electrons systems well-know for their structural, magnetic, charge and superconducting instabilities. In underdoped compound (i.e. for doping less than optimal for superconductivity) a dip in the onset temperature for superconductivity Tc, centered at p∼0.125, occurs. While the origin of this dip is still under debate, most of the experimental evidence in La2-xSrxCuO4 (LSCO) seems to point toward a competition with frozen magnetism1.
In order to further investigate the relationship between magnetism and superconductivity we have performed measurements of ultrasonic velocity and attenuation in LSCO. Around p=1/8, several anomalies are observed in the sound velocity and attenuation, associated with superconductivity and magnetic freezing. The competition between the two orders parameters is tuned with a magnetic field which enhances magnetic correlations at the expense of superconductivity2.
[1] M. H. Julien, Physica B 329-333 (2000) 693.
[2] J. Chang et al., Phys. Rev. B 78 (2008) 104525.
In order to further investigate the relationship between magnetism and superconductivity we have performed measurements of ultrasonic velocity and attenuation in LSCO. Around p=1/8, several anomalies are observed in the sound velocity and attenuation, associated with superconductivity and magnetic freezing. The competition between the two orders parameters is tuned with a magnetic field which enhances magnetic correlations at the expense of superconductivity2.
[1] M. H. Julien, Physica B 329-333 (2000) 693.
[2] J. Chang et al., Phys. Rev. B 78 (2008) 104525.
*We acknowledge support from CNRS, European Magnetic Field Laboratory, French ANR (UNESCOS, contract ANR-14-CE05-0007), the Laboratoire d’Excellence LANEF (ANR-10-LABX-51-01) and the Université Grenoble-Alpes (SMIng-AGIR)
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Presenters
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Mehdi Frachet
- LNCMI - CNRS
- LNCMI