A New Cumulant Expansion Based Extraction for Higher Order Quantum Corrections in Equilibrium Wigner-Boltzmann Equation

A Cumulant based method has been introduced to extract quantum corrections in distribution function with the equilibrium Wigner-Boltzmann equation. It is shown that unlike the moment expansion used in hydrodynamic model, cumulant expansion converges much faster when distribution function is closed to Maxwellian with only first three cumulants are non-zero. In this case, quantum corrections higher than first order can be extracted mainly by lowest three cumulants and odd number derivatives of potential function. This method also provides a new way to determine the distribution function with Maxwellian form and study the role of potential function in quantum correction field.