Correlation between scale-invariant normal state resistivity and superconductivity in an electron-doped cuprate

• Published in: arXiv.org
• Main Authors: Sarkar, Tarapada, Mandal, P R, Poniatowski, N R, Chan, M K, Greene, Richard L
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 08.10.2018
• Subjects: Critical point; Cuprates; Electrical resistivity; High temperature; Magnetic fields; Magnetoresistance; Magnetoresistivity; Physics - Applied Physics; Physics - Strongly Correlated Electrons; Physics - Superconductivity; Superconductivity
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1810.03499

An understanding of the normal state in the high-temperature superconducting cuprates is crucial to the ultimate understanding of the long-standing problem of the origin of the superconductivity itself. This so-called strange metal state is thought to be associated with a quantum critical point (QCP) hidden beneath the superconductivity(1,2). In electron-doped cuprates in contrast to hole-doped cuprates it is possible to access the normal state at very low temperatures and low magnetic fields to study this putative QCP and to probe the T~0 K state of these materials(3,4). We report measurements of the low temperature normal state magnetoresistance (MR) of the n-type cuprate system La2-xCexCuO4 (LCCO) and find that it is characterized by a linear-in-field behavior, which follows a scaling relation with applied field and temperature, for doping (x) above the putative QCP (x= 0.14)(5). This unconventional behavior suggests that magnetic fields probe the same physics that gives rise to the anomalous low-temperature linear-in-T resistivity(4). The magnitude of the linear MR decreases as Tc decreases and goes to zero at the end of the superconducting dome (x ~0.175) above which a conventional quadratic MR is found. These results show that there is a strong correlation between the quantum critical excitations of the strange metal state and the high-Tc superconductivity.