Spontaneous Symmetry Breaking in Finite Systems

Nonperturbative Spontaneous Symmetry Breaking

One of the most astonishing results of quantum field theory is spontaneous symmetry breaking. One can say that it is the situation when something arises from the quantization. This means that on the quantum level one has something that was not present on the classical level. Coleman and Weinberg [1] write : “ . . . higher-order effects may qualitatively change the character of a physical theory...

Spontaneous Symmetry Breaking

Spontaneous symmetry breaking in vortex systems with two repulsive lengthscales

Scanning Hall probe microscopy (SHPM) has been used to study vortex structures in thin epitaxial films of the superconductor MgB2. Unusual vortex patterns observed in MgB2 single crystals have previously been attributed to a competition between short-range repulsive and long-range attractive vortex-vortex interactions in this two band superconductor; the type 1.5 superconductivity scenario. Our...

Melting and spontaneous symmetry breaking in two-dimensional colloidal systems

Renormalization in Quantum Statistics of Systems with Spontaneous Symmetry Breaking

Renormalization in quantum statistics in the presence of a charge associated to a spontaneously broken symmetry is discussed for the scalar field model. In contrast with the case of non-broken symmetry, the renormalization mass counter term δm depends on the chemical potential. We argue that this is connected to the ill-defined character of the charge operator. 1 Permanent address: Grupo de Fis...