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Full-Text Articles in Physical Sciences and Mathematics
Tachyonic Instability And Dynamics Of Spontaneous Symmetry Breaking, Gary Felder, Lev Kofman, Andrei Linde
Tachyonic Instability And Dynamics Of Spontaneous Symmetry Breaking, Gary Felder, Lev Kofman, Andrei Linde
Physics: Faculty Publications
Spontaneous symmetry breaking usually occurs due to the tachyonic (spinodal) instability of a scalar field near the top of its effective potential at φ=0. Naively, one might expect the field φ to fall from the top of the effective potential and then experience a long stage of oscillations with amplitude O(v) near the minimum of the effective potential at φ=v until it gives its energy to particles produced during these oscillations. However, it was recently found that the tachyonic instability rapidly converts most of the potential energy V(0) into the energy of colliding classical waves of the scalar field. This …
Dynamics Of Symmetry Breaking And Tachyonic Preheating, Gary Felder, Juan García-Bellido, Patrick B. Greene, Lev Kofman, Andrei Linde, Igor Tkachev
Dynamics Of Symmetry Breaking And Tachyonic Preheating, Gary Felder, Juan García-Bellido, Patrick B. Greene, Lev Kofman, Andrei Linde, Igor Tkachev
Physics: Faculty Publications
We reconsider the old problem of the dynamics of spontaneous symmetry breaking (SSB) using 3D lattice simulations. We develop a theory of tachyonic preheating, which occurs due to the spinodal instability of the scalar field. Tachyonic preheating is so efficient that SSB typically completes within a single oscillation as the field rolls towards the minimum of its effective potential. We show that, contrary to previous expectations, preheating in hybrid inflation is typically tachyonic. Our results may also be relevant for the theory of the formation of topological defects and of disoriented chiral condensates in heavy ion collisions.
Simultaneous Measurement Of Changes In Thickness And Refractive Index Of Weakly Absorbing Self-Standing Solid Films Using Optical Interferometry, Nalini Easwar, R. Fantini, E. Willis
Simultaneous Measurement Of Changes In Thickness And Refractive Index Of Weakly Absorbing Self-Standing Solid Films Using Optical Interferometry, Nalini Easwar, R. Fantini, E. Willis
Physics: Faculty Publications
A nondestructive optical interferometric method, which enables a direct and simultaneous measurement of small changes in both thickness and refractive index of thin films, is described. Optical interferometric methods are sensitive to the changes in the optical path length (the product of the refractive index and the physical thickness) through the film. Thus, when the film is subjected to changing environmental conditions such as changing temperature or humidity, it is a challenge to determine the change in thickness and the change in refractive index separately, using interferometry. By simultaneously monitoring two different sets of interference fringes, i.e., transmission and reflection …
Development Of Equilibrium After Preheating, Gary Felder, Lev Kofman
Development Of Equilibrium After Preheating, Gary Felder, Lev Kofman
Physics: Faculty Publications
We present a fully nonlinear study of the development of equilibrium after preheating. Preheating is the exponentially rapid transfer of energy from the nearly homogeneous inflaton field to fluctuations of other fields and/or the inflaton itself. This rapid transfer leaves these fields in a highly nonthermal state with energy concentrated in infrared modes. We have performed lattice simulations of the evolution of interacting scalar fields during and after preheating for a variety of inflationary models. We have formulated a set of generic rules that govern the thermalization process in all of these models. Notably, we see that once one of …
Quantum Confinement Transition In A D-Wave Superconductor, Courtney Lannert, T. Senthil, Matthew P. Fisher
Quantum Confinement Transition In A D-Wave Superconductor, Courtney Lannert, T. Senthil, Matthew P. Fisher
Physics: Faculty Publications
We study the nature of the zero-temperature phase transition between a d-wave superconductor and a Mott insulator in two dimensions. In this "quantum confinement transition", spin and charge are confined to form the electron in the Mott insulator. Within a dual formulation, direct transitions from d-wave superconductors at half-filling to insulators with spin-Peierls (as well as other) order emerge naturally. The possibility of striped superconductors is also discussed within the dual formulation. The transition is described by nodal fermions and bosonic vortices, interacting via a long-ranged statistical interaction modeled by two coupled Chern-Simons gauge fields, and the critical properties of …
Electron Spectral Function In Two-Dimensional Fractionalized Phases, Courtney Lannert, Matthew P.A. Fisher, T. Senthil
Electron Spectral Function In Two-Dimensional Fractionalized Phases, Courtney Lannert, Matthew P.A. Fisher, T. Senthil
Physics: Faculty Publications
We study the electron spectral function of various zero-temperature spin-charge separated phases in two dimensions. In these phases, the electron is not a fundamental excitation of the system, but rather “decays” into a spin-1/2 chargeless fermion (the spinon) and a spinless charge e boson (the chargon). Using low-energy effective theories for the spinons (d-wave pairing plus possible Néel order) and the chargons (condensed or quantum-disordered bosons), we explore three phases of possible relevance to the cuprate superconductors: (1) (formula presented) a fractionalized antiferromagnet where the spinons are paired into a state with long-ranged Néel order and the chargons are 1/2-filled …