论文标题
通过施加压力并减少电荷转移差距来增强最大超导温度
Enhancement of maximum superconducting temperature by applying pressure and reducing the charge transfer gap
论文作者
论文摘要
最新扫描的隧道光谱（STS）测量不足的铜层的测量发现当电荷传输差距（CTG）的大小减少时，最大超导过渡温度的增加$ t_c $。施加压力是增加最大$ T_C $的另一种众所周知的方法。但是，这些压力实验还发现了另一个难题，即$ T_C $在不足和最佳的掺杂样品中增强了，但被抑制了过多。在这里，我们提出了一种基于电荷波动的可能机制，可以同时解释这两种效果。从3频段哈伯德型号开始，我们检索了氧气2 $ p^6 $ band和铜3 $ d^{10} $ band之间的电荷波动（CF），该器在$ t-j $型号中被忽略。通过变异蒙特卡洛法（VMC）研究了该模型。
Recent Scanning Tunneling Spectra(STS) measurement on underdoped cuprate discovers the increase of the maximum superconducting transition temperature $T_c$ when the size of charge transfer gap (CTG) is reduced. Applying pressure is another well known method to increase maximum $T_c$. However, these pressure experiments also found another puzzle that $T_c$ is enhanced in underdoped and optimal doped samples but suppressed in overdoped. Here we present a possible mechanism based on the charge fluctuation to explain both these two effects simultaneously. Starting from 3-band Hubbard model, we retrieve the charge fluctuation(CF) between oxygen 2$p^6$ band and copper 3$d^{10}$ band which is ignored in the $t-J$ model. This model is studied via variational Monte Carlo method(VMC).
