A5089037553- Black Holes and Theoretical Physics
- Particle physics theoretical and experimental studies
- Cosmology and Gravitation Theories
- Cold Atom Physics and Bose-Einstein Condensates
- Quantum Chromodynamics and Particle Interactions
- Quantum Information and Cryptography
- Quantum many-body systems
- Physics of Superconductivity and Magnetism
- Quantum Mechanics and Applications
- High-Energy Particle Collisions Research
- Quantum Electrodynamics and Casimir Effect
- Quantum Computing Algorithms and Architecture
- Quantum and electron transport phenomena
- Topological Materials and Phenomena
- Quantum, superfluid, helium dynamics
- Dark Matter and Cosmic Phenomena
- Advanced Thermodynamics and Statistical Mechanics
- Spectroscopy and Quantum Chemical Studies
- Particle Detector Development and Performance
- Noncommutative and Quantum Gravity Theories
- Pulsars and Gravitational Waves Research
- Superconducting Materials and Applications
- Advanced Mathematical Physics Problems
- High-pressure geophysics and materials
- Solar and Space Plasma Dynamics
Université de Montréal
2015-2024
Lawrence Berkeley National Laboratory
1981-1994
European Organization for Nuclear Research
1981-1993
Université du Québec
1991
The Ohio State University
1988-1989
University of Cambridge
1983-1988
University of California, Santa Barbara
1982-1984
General Electric (United States)
1952-1954
United Kingdom Atomic Energy Authority
1954
This is an elementary, self-contained review of some peculiarities quantum mechanics for 2+1 dimensional systems that are at least instructive and perhaps important. In particular, we argue angular momentum need not be quantized statistics interpolating between Fermi Bose can constructed. There possible direct applications to collective excitations in solids cosmic strings, important moral lesson regarding the “wave function universe.”
The possibility is discussed that the lowest-energy state for certain quantum numbers involves a Higgs field polarized into skyrmion-type configuration. In some models new type of vacuum instability arises. Phenomenological consequences are indicated schematically.
The value and limitations of the adiabatic method for calculating induced charges are discussed in a general way illustrated some simple models 1+1 dimensions. relevance size solitons is emphasized.
The contribution of explicit field terms appearing in the Lagrangian (Chern-Simons and θ-terms) to calculation particle statistics is analyzed. Chern-Simons term halves current-field coupling 2 + 1 dimensions. effect θ-term 3 dimensions contrasted. In both cases, observational differences between fundamental induced charges arise. factor 1/2 necessary reconcile Paranjape's result on angular momentum (L = 1/4) a vortex minimal massive QED with general spin-statistics connection. Issues...
We consider a Su-Schrieffer-Heeger (SSH) chain to each end of which we attach semi-infinite undimerized (lead). study the effect openness SSH model on its properties. A representation infinite system using an effective Hamiltonian allows us examine low-energy states in more detail. show that, as one would expect, edge topological phase hybridize coupling between systems is increased. As this grows, these are gradually suppressed, disappearing goes infinity. In topologically trivial phase, no...
We consider the decay of vortices trapped in false vacuum a theory scalar electrodynamics $2+1$ dimensions. The potential is inspired by models with intermediate symmetry breaking to metastable that completely breaks $U(1)$ symmetry, while true vacuum, unbroken. unstable through formation bubbles; however, rate can be extremely long. On other hand, contain vortex solutions. These inside addition unit magnetic flux and appropriate topologically nontrivial outside. numerically establish...
A new and intuitive perturbative approach to time-dependent quantum mechanics problems is presented, which useful in situations where the evolution of Hamiltonian slow. The state a system starts an instantaneous eigenstate initial written as power series has straightforward diagrammatic representation. Each term corresponds sequence ``adiabatic'' evolutions, during remains Hamiltonian, punctuated by transitions from one another. first this standard adiabatic evolution, next well known...
We analyze the validity of adiabatic approximation, and in particular reliability what has been called ``standard criterion'' for this approximation. Recently, criterion found to be insufficient. will argue that is sufficient only when it agrees with intuitive notion slowness evolution Hamiltonian. However, can insufficient cases where Hamiltonian varies rapidly but by a small amount. also emphasize distinction between theorem two quite different, although closely related, ideas.
These lectures are intended as an introduction to the technique of path integrals and their applications in physics. The audience is mainly first-year graduate students, it assumed that reader has a good foundation quantum mechanics. No prior exposure assumed, however. integral formulation mechanics equivalent standard formulations, offering new way looking at subject which is, arguably, more intuitive than usual approaches. Applications vast those itself, including single particle,...
Adiabatic calculations of vacuum polarization fermion fields by solitons are reviewed and extended, their proper interpretation elucidated. Possible in the strong weak interactions discussed as examples. It is emphasized that ground-state charge can depend on scale soliton, with adiabatic result holding for fermions large mass. The very different physical implications effects scalar mentioned. dual phenomenon, whereby heavy particles carrying conserved quantum numbers induce solitons,...
We consider the decay of cosmic strings that are trapped in false vacuum a theory scalar electrodynamics $3+1$ dimensions. This paper is $3+1$-dimensional generalization $2+1$-dimensional vortices which we have recently completed [2]. restrict our analysis to case thin-walled occur when large magnetic flux inside string. Thus string looks like tube fixed radius, at it classically stable. The core contains true vacuum, while outside string, separated by thin wall, vacuum. decays tunneling...
The study of the gravitational field produced by a spatially nonlocal, superposed quantum state massive particle is an interesting and active area research. One outstanding issue whether behaves like classical superposition two particles separated spatial distance with half mass at each position. Alternatively, does behave as far more subtle behavior than simple superposition? Quantum theory ideally suited to probe exactly this kind question. We scattering massless scalar on nonlocal...
Topological defects involving distortions of the phenyl ring torsion angles in leucoemeraldine base form polyaniline are studied. A ring-torsional order parameter is introduced; two solitonlike this found, one which has been discussed previously. These solitons anticipated to exhibit a conventional spin-charge relationship, unlike bond-alternation trans-polyacetylene. The creation energies these estimated, and possible experimental signatures relevance neutral charged discussed.