Superconducting memory and trapped magnetic flux in ternary lanthanum polyhydrides

Abstract

Superconducting memory is a promising technology for data storage because of its speed, high energy efficiency, non-volatility, and compatibility with quantum computing devices. However, the need for cryogenic temperatures makes superconducting memory an extremely expensive and specialized device. Ternary lanthanum polyhydrides, due to their high critical temperatures of 240-250 K, represent a convenient platform for studying effects associated with superconductivity in disordered granular systems. In this work, we investigate a trapped magnetic flux and memory effects in recently discovered lanthanum-neodymium (La,Nd)H${}_{10}$ and lanthanum-scandium (La,Sc)H${}_{12}$ superhydrides at a pressure of 175-196 GPa. We use a steady magnetic field of a few Tesla (T) and strong pulsed fields up to 68 T to create the trapped flux state in the compressed superhydrides. We find a clockwise hysteresis of magnetoresistance in cerium CeH${}_{9-10}$ and lanthanum-cerium (La,Ce)H${}_{10+x}$ polyhydrides, a characteristic feature of granular superconductors. A study of the current-voltage characteristics and voltage-temperature curves of the samples with frozen magnetic flux indicates a significant memory effect in La-Sc polyhydrides already at 225-230 K.

Additional Figure 6 was added

References in corpus (7)

• Enhancement of the superconducting critical temperature realized in the La-Ce-H system at moderate pressures
• Efficient route to achieve superconductivity improvement via substitutional La-Ce alloy superhydride at high pressure
• Trapped magnetic flux in hydrogen-rich high-temperature superconductors
• Effect of paramagnetic impurities on superconductivity in polyhydrides: $\text{s}$-wave order parameter in Nd-doped LaH${}_{10}$
• High-temperature superconductivity in hydrides
• Vortex phase dynamics in yttrium superhydride YH${}_6$ at megabar pressures
• Quasi Two-dimensional Vortex Matter in ThH${}_{10}$ Superhydride

Cited by in corpus (2)

• Ternary superhydrides under pressure of Anderson's theorem: Near-record superconductivity in (La,Sc)H${}_{12}$
• Transmission of radio-frequency waves and nuclear magnetic resonance in lanthanum superhydrides