25-30 August 2019
Henry Ford Building
Europe/Berlin timezone

Splitting hairs: Small physical effects in NMR

27 Aug 2019, 10:30
35m
Lecture Hall B (Henry Ford Building)

Lecture Hall B

Henry Ford Building

Invited talk Computation Computation

Speaker

Prof. Juha Vaara (University of Oulu)

Description

Computation of conventional NMR parameters has become routine. There remain, however, interesting physics to be explored. I introduce four topics of this kind.
For the first time, measured $J$-coupling over a van der Waals (vdW) bond, between 129Xe and 3He in a gas-phase nuclear spin co-magnetometer, can be directly compared with quantitative calculations [1]. The latter involve the second virial coefficient of $J$(129Xe-3He) from relativistic potential energy and $J$-coupling curves.
NMR parameters are magnetic field-dependent. So far, only $B$0-dependent 131Xe quadrupole coupling has been found [2]. Experiments on Co(acac)3 -complex [3], where low-lying d-d excitations render the 59Co shift significantly $B$0-dependent, are compared with non-linear response theory for the leading $O$($B$02) terms [4].
Nucleus-specific information can be obtained from changes in light beam polarisation due to interaction with nuclear spins [5]. We predict nuclear spin-induced magnetochiral birefringence and dichroism, as possible reporters of chirality via different indices of refraction when light propagates parallel and antiparallel with spin magnetisation [6].
In a multi-scale study of spin-exchange optical pumping [7], Rb-Xe collisions are extracted from molecular dynamics and analysed using spin dynamics driven by a quantum-chemical spin Hamiltonian. We reproduce the roles of binary collisions and long-lived vdW complexes and, for the first time, see step-wise build-up of 129Xe polarisation upon vdW oscillations.
[1] J. Vaara, M. V. Romalis, Phys. Rev. A, in press (2019)
[2] T. Meersmann, M. Haake, Phys. Rev. Lett. 81, 1211 (1998)
[3] A. M. Kantola, P. Lantto, I. Heinmaa, J. Vaara, J. Jokisaari, in preparation (2019)
[4] P. Manninen, J. Vaara, Phys. Rev. A 69, 022503 (2004)
[5] I. M. Savukov, S.-K. Lee, and M. V. Romalis, Nature 442, 1021 (2006)
[6] L.-j. Fu, J. Cukras, D. Fedotov, S. Coriani, J. Vaara, in preparation (2019)
[7] J. Rantaharju, M. Hanni, J. Vaara, submitted (2019)

Primary author

Prof. Juha Vaara (University of Oulu)

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