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تسجيل مستخدم جديدAbsence of a Zero Temperature Vortex Solid Phase in Strongly Disordered Superconducting Bi Films
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We present low temperature measurements of the resistance in magnetic field of superconducting ultrathin amorphous Bi films with normal state sheet resistances, $R_N$, near the resistance quantum, $R_Q={hbarover {e^2}}$. For $R_N<R_Q$, the tails of the resistive transitions show the thermally activated flux flow signature characteristic of defect motion in a vortex solid with a finite correlation length. When $R_N$ exceeds $R_Q$, the tails become non-activated. We conclude that in films where $R_N>R_Q$ there is no vortex solid and, hence, no zero resistance state in magnetic field. We describe how disorder induced quantum and/or mesoscopic fluctuations can eliminate the vortex solid and also discuss implications for the magnetic-field-tuned superconductor-insulator transition.
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