The von Neumann Lattice Coherent States and Quantum Fluctuations in an Interacting Many-Boson System with Spontaneous Symmetry Breaking

摘要

We consider an interacting many-Boson system with spontaneous symmetry breaking whose order parameter is expressed as the expectation value of the second quantized Boson field operator. We discuss how the effects of the quantum fluctuations can be systematically calculated by making use of the von Neumann lattice coherent states and the generalized Hill-Wheeler variational method.