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In coupled rotor models which describe identical rotating nuclei the nuclear spin states restrict the possible angular momenta of each molecule. There are two mean-field approaches to determining the orientational phase diagrams in such…

Statistical Mechanics · Physics 2012-01-13 Balazs Hetenyi

$^{1}$H-NMR spin-echo measurements of the spin-echo decay $M(2\tau)$ with a decay rate 1/$T_{2}$ and the frequency shift $\Delta\nu/\nu_{0}$ under applied magnetic field $\mathbf{B}$$_{0}$ = 9 T along the a-axis over a temperature range…

Strongly Correlated Electrons · Physics 2009-11-11 Guoqing Wu , P. Ranin , G. Gaidos , W. G. Clark , S. E. Brown , L. Balicas , L. K. Montgomery

In this work, we devise a fast and effective nuclear spin hyperpolarization scheme, which is in principle magnetic field and temperature independent. We use this scheme to experimentally demonstrate polarizations of up to 66% for phosphorus…

Spin ordering in TbBaCo2O5.5 and its temperature transformation is studied. Polymorphism due to the oxygen ordering with the average content close to 5.5 is investigated. One of ceramic samples (I), in addition to the main phase ap x 2ap x…

We have used the Herschel-HIFI instrument to observe both nuclear spin symmetries of amidogen (NH2) towards the high-mass star-forming regions W31C (G10.6-0.4), W49N (G43.2-0.1), W51 (G49.5-0.4) and G34.3+0.1. The aim is to investigate the…

We investigate the dynamic polarization of nuclear spins in a nominally undoped GaAs/Al$_{0.35}$Ga$_{0.65}$As quantum well using two complementary experimental approaches: time-resolved Kerr rotation and optical orientation measurements of…

Mesoscale and Nanoscale Physics · Physics 2025-12-24 M. Kotur , D. Kudlacik , N. E. Kopteva , E. Kirstein , D. R. Yakovlev , K. V. Kavokin , M. Bayer

A theoretical model of hyperfine spectra of nuclear spin conversion of molecular isomers has been developed. The model takes into account the nuclear spin-spin and spin-rotation interactions, as well as the saturation of intramolecular…

Chemical Physics · Physics 2009-11-06 Pavel L. Chapovsky

The equations of state of spin-polarized nuclear matter and pure neutron matter are studied in the framework of the Brueckner-Hartree-Fock theory including a three-body force. The energy per nucleon $E_A(\delta)$ calculated in the full…

Nuclear Theory · Physics 2018-01-17 W. Zuo , U. Lombardo , C. W. Shen

Spin polarized states in nuclear matter with an effective nucleon-nucleon interaction are studied for a wide range of isospin asymmetries and densities. Based on a Fermi liquid theory, it is shown that there are a few possible scenarios of…

Nuclear Theory · Physics 2007-09-22 A. A. Isayev

We have carried out a neutron scattering study of the instantaneous spin-spin correlations in La2CuO4 (T_N = 325 K) over the temperature range 337 K to 824 K. Incident neutron energies varying from 14.7 meV to 115 meV have been employed in…

Strongly Correlated Electrons · Physics 2009-10-31 R. J. Birgeneau , M. Greven , M. A. Kastner , Y. S. Lee , B. O. Wells , Y. Endoh , K. Yamada , G. Shirane

A gradual spin-state transition occurs in LaCoO3 around T~80-120 K, whose detailed nature remains controversial. We studied this transition by means of inelastic neutron scattering (INS), and found that with increasing temperature an…

Strongly Correlated Electrons · Physics 2008-02-22 A. Podlesnyak , S. Streule , J. Mesot , M. Medarde , E. Pomjakushina , K. Conder , M. W. Haverkort , D. I. Khomskii

We develop a method of non-perturbative optical control over adiabatic remagnetisation of the nuclear spin system and apply it to verify the spin temperature concept in GaAs microcavities. The nuclear spin system is shown to exactly follow…

The spin transition in LaCoO3 is investigated by temperature-dependent resonant soft X-ray emission spectroscopy near the Co 2p absorption edges. This element-specific technique is more bulk sensitive with respect to the temperature induced…

Strongly Correlated Electrons · Physics 2011-12-30 M. Magnuson , S. M. Butorin , C. Såthe , J. Nordgren , P. Ravindran

Theoretical model of the coherent control of nuclear spin isomers by microwave radiation has been developed. Model accounts the M-degeneracy of molecular states and molecular center-of-mass motion. The model has been applied to the 13CH3F…

Chemical Physics · Physics 2009-11-07 O. I. Permyakova , E. Ilisca , P. L. Chapovsky

We propose a method for controlling a class of low temperature chemical reactions. Specifically, we show the hydrogen abstraction channel in the reaction of formaldehyde (H$_{2}$CO) and the hydroxyl radical (OH) can be controlled through…

Recent observations of H2 and H3+ in diffuse interstellar sightlines revealed a difference in the nuclear spin excitation temperatures of the two species. This discrepancy comes as a surprise, as H3+ and H2 should undergo frequent…

Astrophysics of Galaxies · Physics 2015-06-11 F. Grussie , M. H. Berg , K. N. Crabtree , S. Gaertner , B. J. McCall , S. Schlemmer , A. Wolf , H. Kreckel

Spin-transfer and spin-orbit torques allow controlling magnetic degrees of freedom in various materials and devices. However, while the transfer of angular momenta between electrons has been widely studied, the contribution of nuclear spins…

Mesoscale and Nanoscale Physics · Physics 2023-10-16 Adam B. Cahaya , Alejandro O. Leon , Mohammad H. Fauzi

Nuclear spins are known to experience spontaneous long-range correlations only below 2.5 mili-Kelvin in superfluid $^3$He. Here we present the first evidence of nuclear spin coupling in molecular hydrogen (H$_2$) at 74-92 Kelvin using…

Materials Science · Physics 2016-02-05 Raina J. Olsen , Jon W. Taylor , Cristian I. Contescu , James R. Morris

In this article, we study control of electron-nuclear spin dynamics at magnetic field strengths where the Larmor frequency of the nucleus is comparable to the hyperfine coupling strength. The quantization axis for the nuclear spin differs…

Quantum Physics · Physics 2009-11-13 Navin Khaneja