By using the WKBJ method, the average of currents and square of the current are calculated, the results show the existence of the current fluctuation, which causes the noise in the circuits.

• 运用WKBJ方法计算了电流平均值和电流平方的平均值，计算结果表明电流涨落是存在的，它是介观电路中主要的量子噪声。