Quantum theory with many degrees of freedom from Monte Carlo Hamiltonian

With our recently proposed effective Hamiltonian via Monte Carlo, we are ab le to compute low energy physics of quantum systems. The advantage is that we can obtain not only the spectrum of ground and excited states, but also wave functions. The previous work has shown the success of this method in ( 1+1)-dimensional quantum mechanical systems. In this work we apply it to hi gher dimensional systems.