A quantum Monte Carlo study of the Josephson effect in a quantum dot Original Research Article

DC Josephson current in a superconductor/a quantum dot/superconductor junction is studied by a quantum Monte Carlo calculation. Dressed temperature Greenʹs functions are evaluated by using the Hirsch–Fye algorithm and the current is obtained when the bias voltage is zero. Our result reproduces that a π-junction is realized when the Coulomb blockade occurs at finite temperatures.