论文标题
在二维超导体中，栅极控制的BCS-BEC交叉
Gate-controlled BCS-BEC crossover in a two-dimensional superconductor
论文作者
论文摘要
Bardeen-Cooper-Schrieffer（BCS）冷凝和Bose-Einstein凝结（BEC）是配对费米昂系统基态的两个极限。我们报告了从BCS凝结到BEC的交叉行为，在二维（2D）超导体，电子掺杂分层材料Zrncl中。该相图通过在离子门下的电阻率和隧穿光谱的同时实验建立，在低掺杂方面证明了伪随相位。在低载体密度极限中，$ t _ {\ rm bkt} $（berezinskii-kosterlitz-二维超导体的无用过渡温度）缩放为$ t _ {\ rm bkt}/t _ {\ rm bkt}/t _ {\ rm f} {\ rm f} = 0.12 $，$ is $ tme consely the f ers form form form f rm the f rm the frm the f rm the frm the f rm rm rmm BCS-BEC交叉状态中预期的理论上限。目前的结果表明，掺杂栅极的半导体为2D BCS-BEC交叉提供了理想的平台，而没有任何附加的复杂性，例如磁性顺序和密度波。
The Bardeen-Cooper-Schrieffer (BCS) condensation and the Bose-Einstein condensation (BEC) are the two extreme limits of the ground state of the paired fermion systems. We report crossover behavior from the BCS condensation to the BEC realized in the two-dimensional (2D) superconductor, electron doped layered material ZrNCl. The phase diagram, established by simultaneous experiments of resistivity and tunneling spectra under the ionic gating, demonstrates the pseudogap phase at the low doping regime. In the low carrier density limit, $T_{\rm BKT}$ (Berezinskii-Kosterlitz-Thouless transition temperature for 2D superconductors) scales as $T_{\rm BKT}/T_{\rm F} = 0.12$, where $T_{\rm F}$ is the Fermi temperature, which is consistent with the theoretical upper bound expected in the BCS-BEC crossover regime. The present results indicate that the gate-doped semiconductor provides an ideal platform for the 2D BCS-BEC crossover without any added complexity, such as magnetic orders and density waves.
