skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Manifestations of quantum phase transitions in transport through nanosystems

Abstract

The award led to several important new results in theory of interacting low-dimensional systems. The results are relevant for both traditional condensed matter systems, such as quantum wires and quantum spin chains, and for the relatively new field of ultra-cold atomic gases.

Authors:
Publication Date:
Research Org.:
Georgia Tech Research Corporation, Atlanta GA
Sponsoring Org.:
USDOE
OSTI Identifier:
1150787
Report Number(s):
DOE-GTRC-ER46311
DOE Contract Number:
FG02-06ER46311
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 77 NANOSCIENCE AND NANOTECHNOLOGY; One-dimensional systems Coulomb drag Luttinger liquid Umklapp scattering Quantum wires Relaxation

Citation Formats

Pustilnik, Michael. Manifestations of quantum phase transitions in transport through nanosystems. United States: N. p., 2014. Web. doi:10.2172/1150787.
Pustilnik, Michael. Manifestations of quantum phase transitions in transport through nanosystems. United States. doi:10.2172/1150787.
Pustilnik, Michael. Thu . "Manifestations of quantum phase transitions in transport through nanosystems". United States. doi:10.2172/1150787. https://www.osti.gov/servlets/purl/1150787.
@article{osti_1150787,
title = {Manifestations of quantum phase transitions in transport through nanosystems},
author = {Pustilnik, Michael},
abstractNote = {The award led to several important new results in theory of interacting low-dimensional systems. The results are relevant for both traditional condensed matter systems, such as quantum wires and quantum spin chains, and for the relatively new field of ultra-cold atomic gases.},
doi = {10.2172/1150787},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Aug 28 00:00:00 EDT 2014},
month = {Thu Aug 28 00:00:00 EDT 2014}
}

Technical Report:

Save / Share:
  • Atomistic-scale behavior drives performance in many micro- and nano-fluidic systems, such as mircrofludic mixers and electrical energy storage devices. Bringing this information into the traditionally continuum models used for engineering analysis has proved challenging. This work describes one such approach to address this issue by developing atomistic-to-continuum multi scale and multi physics methods to enable molecular dynamics (MD) representations of atoms to incorporated into continuum simulations. Coupling is achieved by imposing constraints based on fluxes of conserved quantities between the two regions described by one of these models. The impact of electric fields and surface charges are also critical, hence,more » methodologies to extend finite-element (FE) MD electric field solvers have been derived to account for these effects. Finally, the continuum description can have inconsistencies with the coarse-grained MD dynamics, so FE equations based on MD statistics were derived to facilitate the multi scale coupling. Examples are shown relevant to nanofluidic systems, such as pore flow, Couette flow, and electric double layer.« less
  • This project discovered that non-equilibrium structures, including chemically ordered structures not observed in bulk systems, form in isolated nanoscale systems. Further, a generalized model was developed that effectively explained the suppression of equilibrium phase transformations. This thermodynamic model considered the free energy decrease associated with the phase transformation was less than the increase in energy associated with the formation of an interphase interface, therefore inhibiting the phase transformation. A critical diameter exists where the system transitions to bulk behavior, and a generalized equation was formulated that successfully predicted this transition in the Fe-Au system. This provided and explains a newmore » route to novel structures not possible in bulk systems. The structural characterization was accomplished using transmission electron microscopy in collaboration with Matthew Kramer of Ames Laboratory. The PI and graduate student visited Ames Laboratory several times a year to conduct the experiments.« less
  • It is commonly believed that in confining vector-like gauge theories the center and chiral symmetry realizations are parametrically entangled, and if phase transitions occur, they must take place around the strong scale {Lambda}{sup -1} of the gauge theory. We demonstrate that (non-thermal) vector-like theories formulated on R{sup 3} x S{sup 1} where S{sup 1} is a spatial circle exhibit new dynamical scales and new phenomena. There are chiral phase transitions taking place at {Lambda}{sup -1}/N{sub c} in the absence of any change in center symmetry. {Lambda}{sup -1}/N{sub c}, invisible in (planar) perturbation theory, is also the scale where abelian versusmore » non-abelian confinement regimes meet. Large N{sub c} volume independence (a working Eguchi-Kawai reduction) provides new insights and independently confirms the existence of these scales. We show that certain phases and scales are outside the reach of holographic (supergravity) modeling of QCD.« less
  • The dynamics of a second-order phase transition during inflation, which is induced by time-variation of spacetime curvature, is studied as a natural mechanism to produce topological defects of typical grand unification scales such as cosmic strings or global textures. It is shown that their distribution is almost scale-invariant with small- and large-scale cutoffs. Also discussed is how these cutoffs are given.
  • Lectures are given on a nonperturbative approach to quantum field theories. Phenomena are discussed for which the usual weak coupling perturbative approach in terms of Feynman diagrams is of no assistance. Properties associated with large distance behavior, i.e., phase transitions, low lying spectra, coherent excitations which are presumably built out of the long wave structure of the theory are described. These methods are important for the study of strong coupling field theories and the question of quarks confinement. 25 references. (JFP)