Capriotti Luca, Cuccoli Alessandro, Fubini Andrea, Tognetti Valerio, Vaia Ruggero
Valuation Risk Group, Credit Suisse First Boston (Europe) Ltd., One Cabot Square, London E14 4QJ, United Kingdom.
Phys Rev Lett. 2005 Apr 22;94(15):157001. doi: 10.1103/PhysRevLett.94.157001. Epub 2005 Apr 21.
We analyze the interplay of dissipative and quantum effects in the proximity of a quantum phase transition. The prototypical system is a resistively shunted two-dimensional Josephson junction array, studied by means of an advanced Fourier path-integral Monte Carlo algorithm. The reentrant superconducting-to-normal phase transition driven by quantum fluctuations, recently discovered in the limit of infinite shunt resistance, persists for moderate dissipation strength but disappears in the limit of small resistance. For large quantum coupling our numerical results show that, beyond a critical dissipation strength, the superconducting phase is always stabilized at sufficiently low temperature. Our phase diagram explains recent experimental findings.
我们分析了量子相变附近耗散效应和量子效应的相互作用。典型系统是一个电阻分流二维约瑟夫森结阵列，通过先进的傅里叶路径积分蒙特卡罗算法进行研究。最近在无限分流电阻极限下发现的由量子涨落驱动的再入超导 - 正常相变，在中等耗散强度下持续存在，但在小电阻极限下消失。对于大的量子耦合，我们的数值结果表明，超过临界耗散强度后，超导相在足够低的温度下总是稳定的。我们的相图解释了最近的实验结果。
