Universal relaxational dynamics near two-dimensional quantum-critical points
| dc.creator | Sachdev, Subir | |
| dc.date | 1998-10-30 | |
| dc.date | 1999-02-12 | |
| dc.date.accessioned | 2026-07-07T03:11:51Z | |
| dc.date.available | 2026-07-07T03:11:51Z | |
| dc.description | We describe the nonzero temperature (T), low frequency (ω) dynamics of the order parameter near quantum critical points in two spatial dimensions (d), with a special focus on the regime \hbarω<< k_B T. For the case of a `relativistic', O(n)-symmetric, bosonic quantum field theory we show that, for small ε=3-d, the dynamics is described by an effective classical model of waves with a quartic interaction. We provide analytical and numerical analyses of the classical wave model directly in d=2. We describe the crossover from the finite frequency, "amplitude fluctuation", gapped quasiparticle mode in the quantum paramagnet (or Mott insulator), to the zero frequency "phase" (n >= 2) or "domain wall" (n=1) relaxation mode near the ordered state. For static properties, we show how a surprising, duality-like transformation allows an exact treatment of the strong-coupling limit for all n. For n=2, we compute the universal T dependence of the superfluid density below the Kosterlitz-Thouless temperature, and discuss implications for the high temperature superconductors. For n=3, our computations of the dynamic structure factor relate to neutron scattering experiments on La_{1.85}Sr_{0.15}CuO_4, and to light scattering experiments on double layer quantum Hall systems. We expect that closely related effective classical wave models will apply also to other quantum critical points in d=2. | |
| dc.description | 45 pages including 12 figures. Although appendices use technical results from earlier papers, the physical discussion in the body of the paper is self-contained | |
| dc.identifier | https://arxiv.org/abs/cond-mat/9810399 | |
| dc.identifier | http://arxiv.org/abs/cond-mat/9810399 | |
| dc.identifier | Phys.Rev. B59 (1999) 14054 | |
| dc.identifier | doi:10.1103/PhysRevB.59.14054 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/28735 | |
| dc.subject | Strongly Correlated Electrons | |
| dc.subject | Superconductivity | |
| dc.subject | High Energy Physics - Lattice | |
| dc.title | Universal relaxational dynamics near two-dimensional quantum-critical points | |
| dc.type | text |