Nuclear spin relaxation at ultralow temperatures

Article

关键词: NEGATIVE NANOKELVIN TEMPERATURES;    LATTICE RELAXATION;    SILVER;    COPPER;   

DOI  :  10.1103/PhysRevB.59.9462

来源: SCIE

【 摘 要 】

Nuclear spin relaxation induced by hyperfine coupling is studied theoretically at positive and negative submicrokelvin temperatures. By avoiding the assumption of the high-temperature limit, adopted in conventional theories, we derive a formula in which the relaxation rate is expressed in terms of thermal averages of nuclear spin energies. The exchange interaction induces an asymmetry in the energy spectrum, which leads to relaxation rates that depend on whether the nuclear spin temperature is positive or negative. High-temperature expansion methods and Monte Carlo simulations are applied to explain the anomalous results by Hakonen ct al. in rhodium qualitatively. [S0163-1829(99)12313-0].

【 授权许可】

Free