arXiv subjects
Publications and source records attributed to Zhong Tang.
Let a quantum network be a Fermi-Dirac assembly of Fermi-Dirac assemblies of ...of quantum points, interpreted topologically. The simplest quantum-network vacuum modes with exact conservation of relativistic energy-momentum and angular momentum also support the local non-Abelian groups of the standard model, torsion and gravity. The spacetime points of these models naturally obey parastatistics. We construct a left-handed vacuum network among others.
Seeking a relativistic quantum infrastructure for gauge physics, we analyze spacetime into three levels of quantum aggregation analogous to atoms, bonds and crystals. Quantum spacetime points with no extension make up more complex link units with microscopic extension, which make up networks with macroscopic extension. Such a multilevel quantum theory implies parastatistics for the lowest level entities without additional physical assumptions. Any hypercubical vacuum mode with off-diagonal long-range order that is covariant under $\POINCARE$ also has bonus internal symmetries somewhat like those of the standard model. A vacuum made with the dipole link proposed earlier has too much symmetry. A quadrupole link solves this problem.
We develop a new transformation theory in quantum physics, where the transformation operators, defined in the infinite dimensional Hilbert space, have right-unitary inverses only. Through several theorems, we discuss the properties of state space of such operators. As one application of the right-unitary transformation (RUT), we show that using the RUT method, we can solve exactly various interactions of many-level atoms with quantized radiation fields, where the energy of atoms can be two levels, three levels in Lambda, V and equiv configurations, and up to higher (>3) levels. These interactions have wide applications in atomic physics, quantum optics and quantum electronics. In this paper, we focus on two typical systems: one is a two-level generalized Jaynes-Cummings model, where the cavity field varies with the external source; the other one is the interaction of three-level atom with quantized radiation fields, where the atoms have Lambda-configuration energy levels, and the radiation fields are one-mode or two-mode cavities.
We provide an alternative interpretation for the topological terms in physics by investigating the low-energy gauge interacting system. The asymptotic behavior of the gauge field at infinity indicates that it traces out a closed loop in the infinite time interval: -infinity, + infinity. Adopting Berry's argument of geometric phase, we show that the adiabatic evolution of the gauge system around the loop results in an additional term to the effective action: the Chern-Simons term for three-dimensional spacetime, and the Pontrjagin term for the four-dimensional spacetime.
We introduce topological magnetic field in two-dimensional flat space, which admits a solution of scalar monopole that describes the nontrivial topology. In the Chern-Simons gauge field theory of anyons, we interpret the anyons as the quasi-particles composed of fermions and scalar monopoles in such a form that each fermion is surrounded by infinite number of scalar monopoles. It is the monopole charge that determines the statistics of anyons. We re-analyze the conventional arguments of the connection between topology and statistics in three-dimensional space, and find that those arguments are based on the global topology, which is relatively trivial compared with the monopole structure. Through a simple model, we formulate the three-dimensional anyon field using infinite number of Dirac's magnetic monopoles that change the ordinary spacetime topology. The quasi-particle picture of the three-dimensional anyons is quite similar to that of the usual two-dimensional anyons. However, the exotic statistics there is not restricted to the usual fractional statistics, but a functional statistics.
We construct a relativistically covariant symmetry of QED. Previous local and nonlocal symmetries are special cases. This generalized symmetry need not be nilpotent, but nilpotency can be arranged with an auxiliary field and a certain condition. The Noether charge generating the symmetry transformation is obtained, and it imposes a constraint on the physical states.