Fabrication and transport properties of two dimensional Bi2Sr2Ca2Cu3O10+δ micro-bridge

Abstract

Ultra-thin high-temperature superconducting films have attracted continuous interest due to their potential electronic applications, which also provide a unique platform of novel physics and properties in the two-dimensional limit. We, here, realized fabrication of two-unit-cell-thick micro-bridges from mechanically exfoliated ultra-thin Bi2Sr2Ca2Cu3O10+δ (Bi2223) single crystals and systematically investigated their transport properties. The two-dimensional superconducting nature is verified by the existence of the Berezinskii–Kosterlitz–Thouless transition, which is simultaneously revealed by current-voltage properties and the zero-field temperature dependence of resistance. Comparing with Bi2223 bulk crystal, a Bi2223 micro-bridge shows a slight lower upper critical field but pronounced improvement in the critical current density. Our findings indicate that the ultra-thin Bi2223 single crystal is highly prospective for both scientific investigations of unconventional superconductivity and applications of high Tc superconducting devices.

Two-Dimensional Superconductivity in Air-Stable Single-Crystal Few-Layer Bi3O2S3

“…Application of current leads to unbinding of the vortex–antivortex pairs. Consequently, power-law dependence in the current–voltage curves is expected in the 2D superconducting systems at temperatures below T BKT , and a universal scaling relationship of V ∝ I 3 can be expected at T BKT . In addition, the bound vortices can be totally dissociated when the bias current is sufficiently large where the superconducting states disappear.…”

“…Consequently, power-law dependence in the current−voltage curves is expected in the 2D superconducting systems at temperatures below T BKT , and a universal scaling relationship of V ∝ I 3 can be expected at T BKT . 48 In addition, the bound vortices can be totally dissociated when the bias current is sufficiently large where the superconducting states disappear. When the temperature exceeds T BKT , some bound vortex− antivortex pairs still exist in the temperature range (T BKT ∼ T C ).…”

Extremely fast vortices dynamics in Bi2Sr2Ca2Cu3O10+δ crystalline nanostrip

“…Although the oxygen atoms of ultra-thin Bibased high T c superconductor are prone to degrade even under ambient conditions when reduce the thickness down to 0.5 U.C., [39] and cryogenic cleavage is necessitated for ultra-thin Bi-based high T c superconductor in constructing twisted cuprate superconductors. [40] However, recent experiments [36,41] showed that thin flakes of Bi-based high T c superconductor exfoliated at room temperature still maintain relatively high T c for films with thickness more than 2 U.C. if the exposure time to ambient environment is limited within 20 min.…”

“…The detailed fabrication process of Bi2223 sub-microbridge is described elsewhere. [36] As shown in Fig. S1 of the supplementary material, characteristic curves of resistance and current versus voltage are measured by a standard four-wire method by using a resistance bridge and electrical transport options of physical property measurement system (PPMS, Quantum Design).…”

“…[34,35] Based on these previous investigations, a high T c superconducting microbridge with good bridge-edge would be an optimal platform for accessing extremely fast vortex dynamics. [36] To this end, we here fabricated Bi 2 Sr 2 Ca 2 Cu 3 O 10+δ (Bi2223) nanostrips by direct laser writing to avoid possible degradations from electron beam lithography, and milling by an Ar ion beam. The normal resistivity of the resulting nanostrip is around 220 µΩ • cm (T = 120 K), and the vortex velocities deduced from the current-voltage (I-V ) characteristics can be up to three hundreds of kilometers per second.…”