Effectively tuning the quantum Griffiths phase by controllable quantum fluctuations.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 39602548.
- Also identified by DOI 10.1126/sciadv.adp1402 and PMC identifier 11601250.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Quantum Griffiths phase (QGP), marked by a quantum Griffiths singularity with a divergent effective critical exponent, has garnered considerable attention in the realm of superconductivity. However, the ability to control QGP remains elusive. Here, we demonstrate that QGP at the LaAlO<sub>3</sub>/KTaO<sub>3</sub>(110) interface can be efficiently modulated by the orientation of applied magnetic field: With a perpendicular field, an anomalous QGP emerges in the low-temperature regime, characterized by a decreasing critical field as temperature lowers; conversely, with a parallel field, a normal QGP arises, where the critical field increases with decreasing temperature. Such opposite characteristics stem from the controllable quantum fluctuations and conductivity corrections under distinct magnetic field orientations. Furthermore, we show the effective tuning of the phase boundary by electrostatic gating, attributed to the gate-controlled quantum fluctuations. These findings not only demonstrate how to experimentally manipulate QGP but also provide a comprehensive understanding of how quantum fluctuations can effectively modulate QGP.