Vortex Phase Dynamics in Yttrium Superhydride YH6 at Megabar Pressures
Andrey V Sadakov1, Vladimir A Vlasenko1, Ivan A Troyan2
1P. N. Lebedev Physical Institute, Russian Academy of Sciences, Moscow 119991, Russia.
The Journal of Physical Chemistry Letters
|July 18, 2023
Summary
This study investigates vortex phases in the high-temperature superconductor YH₆, revealing high flux flow barriers and a distinct vortex phase diagram. These findings position YH₆ as a promising material for advanced superconducting applications.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Superconductivity
Background:
- High-temperature superconductors, particularly hydrides, are crucial for advancing superconducting technologies.
- Understanding vortex dynamics and phase transitions is key to optimizing superconductor performance under extreme conditions.
Purpose of the Study:
- To comprehensively study vortex phases and dynamics in YH₆ at 215 K and 200 GPa.
- To determine the thermal activation energy and analyze vortex phase transitions.
- To construct the first vortex phase diagram for superhydrides.
Main Methods:
- Application of the thermally activated flux flow (TAFF) theory to derive thermal activation energy (U₀).
- Analysis of magnetic field dependence of U₀, including power law and crossover fields.
- Utilizing vortex-glass theory to describe the transition from vortex-glass to vortex-liquid states.
Main Results:
- YH₆ exhibits a high critical temperature (T<0xE1><0xB5><0xA_>) onset of 215 K at 200 GPa.
- Derived thermal activation energy U₀ follows a power law U₀ ∝ H^α with a crossover around 8-10 T.
- Vortex phase diagram constructed, showing high flux flow barriers (1.5-7 × 10⁴ K) and high crossover fields.
- Ginzburg number (3-7 × 10⁻³) indicates limited broadening of superconducting transitions by thermal fluctuations.
Conclusions:
- YH₆ is an outstanding superconductor compared to cuprates and iron-based systems due to high flux flow barriers and crossover fields.
- The material demonstrates robust superconducting properties with limited thermal fluctuation effects.
- The established vortex phase diagram provides critical insights for future research and applications of superhydrides.
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