NMR relaxation in the spin-1 Heisenberg chain

Sylvain Capponi (1, 2, 3) , Maxime Dupont (4, 5, 1, 2, 3) , Anders W Sandvik (1, 6) , Pinaki Sengupta (7)

1 Department of Physics [Boston]
2 FFC - Fermions Fortement Corrélés (LPT)
3 LPT - Laboratoire de Physique Théorique
4 Department of Physics [Berkeley]
5 LBNL - Lawrence Berkeley National Laboratory [Berkeley]
6 Beijing National Laboratory for Condensed Matter Physics
7 SPMS-PAP-02-01 - Division of Physics and Applied Physics [Nanyang Technological University]

We consider the isotropic S = 1 Heisenberg chain with a finite Haldane gap ∆ and use state-of-the-art numerical techniques to investigate its dynamical properties at finite temperature, focusing on the nuclear spin-lattice relaxation rate 1/T1 measured in nuclear magnetic resonance (NMR) experiments for instance. In particular, we analyze the contributions from modes with momenta close to q ≈ 0 and q ≈ π as a function of temperature. At high-temperature we observe spin diffusion, while at low-temperature we argue that a simple activated behavior 1/T1 ∝ exp(−∆/T) can be observed only at temperatures much smaller than the gap ∆.

Domaines: Electrons fortement corrélés [cond-mat.str-el]

Sylvain Capponi, Maxime Dupont, Anders W Sandvik, Pinaki Sengupta. NMR relaxation in the spin-1 Heisenberg chain. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2019, 100 (9), pp.094411. ⟨10.1103/PhysRevB.100.094411⟩. ⟨hal-02292630⟩