NMR Investigation of the Low Temperature Dynamics of solid 4He doped with 3He impurities
arXiv:1301.3929 · doi:10.1103/PhysRevB.87.224303
Abstract
The lattice dynamics of solid 4He has been explored using pulsed NMR methods to study the motion of 3He impurities in the temperature range where experiments have revealed anomalies attributed to superflow or unexpected viscoelastic properties of the solid 4He lattice. We report the results of measurements of the nuclear spin-lattice and spin-spin relaxation times that measure the fluctuation spectrum at high and low frequencies, respectively, of the 3He motion that results from quantum tunneling in the 4He matrix. The measurements were made for 3He concentrations 16<x_3<2000 ppm. For 3He concentrations x_3 = 16 ppm and 24 ppm, large changes are observed for both the spin-lattice relaxation time T_1 and the spin-spin relaxation time T_2 at temperatures close to those for which the anomalies are observed in measurements of torsional oscillator responses and the shear modulus. These changes in the NMR relaxation rates were not observed for higher 3He concentrations.
23 pages, 10 figures
References in corpus (11)
- Low Temperature Shear Modulus Changes in Solid 4-He and Connection to Supersolidity
- Observation of Unusual Mass Transport in Solid hcp 4He
- The fate of vacancy-induced supersolidity in 4He
- Evidence for a Superglass State in Solid 4He
- The effect of 3He impurities on the nonclassical response to oscillation of solid 4He
- A Gross-Pitaevskii Treatment for Supersolid He
- Distinguishing between non-orthogonal quantum states of a single spin
- Interplay of Rotational, Relaxational, and Shear Dynamics in Solid 4He
- NMR study of the dynamics of 3He impurities in the proposed supersolid state of solid 4He
- The glassy response of double torsion oscillators in solid Helium-4
- Nuclear Spin Relaxation of Very Dilute 3He impurities in Solid 4He