Phase transition and vortex noise spectrum in two-dimensional Josephson-junction array
二维约瑟夫森结阵列中的相变及噪声频谱研究

Using the resistively shunted junction(RSJ)model,we calculate the temperature dependence of vorticities and fluctuations of vorticities in two-dimensional Josephson junction array(JJA).It is found that the phase transition is of the Berezinski-Kosterlitz-Thouless(KTB)type.We also study the temperature and driving current dependence of the noise power spectrum in the vicinity of phase transition.The calculated results are consistent with recent experimental reports,and the main characteristics of the noise power spectrum can be explained by the motion of vortices.