Competition between spontaneous symmetry breaking and single-particle gaps in trilayer graphene

Spontaneous Symmetry Breaking in Single and Molecular Quantum Dots

Classes of spontaneous symmetry breaking at zero and low magnetic fields in single quantum dots (QD’s) and quantum dot molecules (QDM’s) are discussed in relation to the ratio RW between the interelectron Coulomb repulsion and the harmonic confinement, using spin-and-space unrestricted Hartree-Fock calculations. These include Wigner crystallization for RW . 1, and formation of noncrystallized e...

Spontaneous Symmetry Breaking as a Basis of Particle Mass

Electroweak theory joins electromagnetism with the weak force in a single quantum field theory, ascribing the two fundamental interactions—so different in their manifestations—to a common symmetry principle. How the electroweak gauge symmetry is hidden is one of the most urgent and challenging questions facing particle physics. The provisional answer incorporated in the “standard model” of part...

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

Decoherence induced spontaneous symmetry breaking

We study time dependence of exchange symmetry properties of Bell states when two-qubits interact with local baths having identical parameters. In case of classical noise, we consider a decoherence Hamiltonian which is invariant under swapping the first and second qubits. We find that as the system evolves in time, two of the three symmetric Bell states preserve their qubit exchange symmetry wit...