Quantum Monte Carlo study on magnetization processes

A quantum Monte Carlo method combining update of the loop algorithm with th e global flip of the world line is proposed as an efficient method for stud ying the magnetization process in an external field, which has been difficu lt because of inefficiency of the update of the total magnetization. The me thod is demonstrated in the one dimensional antiferromagnetic Heisenberg mo del and the trimer model. Wie attempted various other Monte Carlo algorithm s to study systems in the external field and compared their efficiency.