Naslov
The Hall response of the Planckian sector in nematic FeSe1-xSx

Autori
Čulo, Matija ; Licciardello, Salvatore ; Ayres, Jake ; Berben, Maarten ; Hsu, Yu-Te ; Kasahara, Shigeru ; Matsuda, Yuji ; Shibauchi, Takasada ; Maksimovic, Nikola ; Analytis, James ; Hussey, Nigel

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, neobjavljeni rad, znanstveni

Skup
SCES 2020 - International Conference on Strongly Correlated Electron Systems

Mjesto i datum
Online, 27.09.2021. - 02.10.2021

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Nije recenziran

Ključne riječi
linar-T resistivity ; quadrature scaling ; quantum critical point ; Planckian limit ; nematicity

Sažetak
The normal state transport properties of many high-temperature superconductors are as intriguing as their unconventional superconductivity (SC). Marked deviations from Fermi liquid (FL) theory (the standard model of metals) have been found, including a robust linear temperature dependence of the resistivity, an unusual quadrature scaling of the magnetoresistance and a pronounced temperature and field dependence of the Hall resistivity. Such behavior is often ascribed to additional scattering caused by proximity to a quantum critical point (QCP) inside the SC dome which can bring charge carriers to the Planckian limit – the maximum dissipation allowed by quantum mechanics. FeSe1-xSx is unique among unconventional superconductors because here SC emerges from an electronic nematic state which exists in isolation (i.e. in the absence of magnetic order) and therefore gives an opportunity to study the relationship between nematic fluctuations and high-temperature SC. Substituting S for Se leaves the SC transition temperature Tc (≈ 10 K) almost unaffected, while the nematic transition temperature is effectively suppressed and is believed to terminate inside the superconducting dome at a critical value xc = 0.17. Our previous dc transport measurements revealed classic signatures of quantum criticality in FeSe1-xSx: a T -linear resistivity within a fan-like region of the phase diagram around the QCP at x = xc, the standard FL T^2 resistivity below the quantum critical fan and an enhancement in the coefficient of the T^2 resistivity on approaching the QCP. Our recent magnetoresistance study in FeSe1-xSx also revealed the existence of two conductivity components: an orbital magnetoresistance that varies quadratically with field (the FL component) and a quantum critical (QC) component that displays unusual quadrature scaling as found in other materials close to their (magnetic) QCP. This study indicated, for the first time, the possibility of the coexistence of two charge sectors in a quantum critical system: one associated with fermionic quasiparticles and the other possibly associated with Planckian QC excitations. In this work we present our most recent Hall effect measurements performed on the same series of single-crystalline FeSe1-xSx samples in high magnetic fields up to 33 T. A detailed analysis reveals that there are also two components in the Hall conductivity: one associated with the FL component (in a perfectly compensated semi-metal) and the other that shows an unusual exponential decay at high fields that we attribute to the QC component. This finding implies that the Planckian sector also contributes to the weak-field Hall response, but vanishes at high fields.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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