Fluctuations in a Quantum Random Heisenberg Paramagnet
| Autor: | M. J. Rozenberg, D. R. Grempel |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Physics
Condensed matter physics Spectral weight Quantum Monte Carlo Dynamic structure factor General Physics and Astronomy Paramagnetism symbols.namesake Quantum mechanics symbols Condensed Matter::Strongly Correlated Electrons Curie constant Hamiltonian (quantum mechanics) Quantum Quantum fluctuation |
| Zdroj: | Physical Review Letters. 80:389-392 |
| ISSN: | 1079-7114 0031-9007 |
| DOI: | 10.1103/physrevlett.80.389 |
| Popis: | We solve the $S\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1/2$ infinite-range random Heisenberg Hamiltonian in the paramagnetic phase using quantum Monte Carlo and analytical techniques. We find that the spin-glass susceptibility diverges at a finite temperature ${T}_{g}$ which demonstrates the existence of a low-temperature ordered phase. Quantum fluctuations reduce the critical temperature and the effective Curie constant with respect to their classical values. They also give rise to a redistribution of spectral weight in the dynamic structure factor in the paramagnetic phase. As the temperature decreases the spectrum of magnetic excitations gradually splits into quasielastic and inelastic contributions whose weights scale as ${S}^{2}$ and $S$ at low temperature. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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