Nuclear magnetic resonance in high magnetic field: Application to condensed matter physics

Berthier, C.; Horvatić, M.; Julien, M.-H.; Mayaffre, H.; Krämer, Steffen

doi:10.1016/j.crhy.2017.09.009

Cited by 21 publications

(14 citation statements)

References 176 publications

(250 reference statements)

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“…Another promising experimental technique for investigating high-temperature hydrodynamics is NMR, which has been successfully used to characterize the low-temperature TLL regime in numerous spin compounds [59,[62][63][64][65][66][67][68][69]. Nuclear spins are polarized via a static magnetic field (ideally weak) and then perturbed by an electromagnetic pulse of frequency 0 , chosen to target specific nuclei as per the Zeeman splitting.…”

mentioning

confidence: 99%

Spatiotemporal Crossover between Low- and High-Temperature Dynamical Regimes in the Quantum Heisenberg Magnet

2021

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The stranglehold of low temperatures on fascinating quantum phenomena in one-dimensional quantum magnets has been challenged recently by the discovery of anomalous spin transport at high temperatures. Whereas both regimes have been investigated separately, no study has attempted to reconcile them. For instance, the paradigmatic quantum Heisenberg spin-1/2 chain falls at low-temperature within the Tomonaga-Luttinger liquid framework, while its high-temperature dynamics is superdiffusive and relates to the Kardar-Parisi-Zhang universality class in 1 + 1 dimensions. This work aims at reconciling the two regimes. Building on large-scale matrix product state simulations, we find that they are connected by a temperature-dependent spatiotemporal crossover. As the temperature is reduced, we show that the onset of superdiffusion takes place at longer length and time scales ∝ 1/ . This prediction has direct consequences for experiments including nuclear magnetic resonance: it is consistent with earlier measurements on the nearly ideal Heisenberg = 1/2 chain compound Sr 2 CuO 3 yet calls for new and dedicated experiments.

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confidence: 99%

Spatiotemporal Crossover between Low- and High-Temperature Dynamical Regimes in the Quantum Heisenberg Magnet

2021

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“…Typically the amount of information in the time simulation grows until the maximal bond dimension is reached. Then, one loses a precision of i at each step by discarding the smallest singular values λ j according to (7), which is mandatory if one wants to keep the numerical algorithmic complexity size χ of the matrices fixed. The algorithm stops when the total discarded weight passes a threshold i∈{all steps} i > 10 −2 or when a single step lacks in precision i > 10 −5 .…”

Section: Ladders Lmentioning

confidence: 99%

Low-dimensional correlations under thermal fluctuations

Kestin

Giamarchi

2019

Phys. Rev. B

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We study the correlation functions of quantum spin 1/2 two-leg ladders at finite temperature, under a magnetic field, in the gapless phase at various relevant temperatures T = 0, momenta q, and frequencies ω. We compute those quantities using the time-dependent density-matrix renormalization group (T-DMRG) in an optimal numerical scheme. We compare these correlations with the ones of dimerized quantum spin chains and simple spin chains, that we compute by a similar technique. We analyze the intermediate energy modes and show that the effect of temperature leads to the formation of an essentially dispersive mode corresponding to the propagation of a triplet mode in an incoherent background, with a dispersion quite different from the one occurring at very low temperatures. We compare the low-energy part of the spectrum with the predictions of the Tomonaga-Luttinger liquid field theory at finite temperature. We show that the field theory describes in a remarkably robust way the low-energy correlations for frequencies or temperatures up to the natural cutoff (the effective dispersion) of the system. We discuss how our results could be tested in, e.g., neutron-scattering experiments. arXiv:1901.04339v2 [cond-mat.str-el]

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“…Magnetic resonance imaging (MRI) systems with a strong main magnetic field, B 0 , such as 7T MRI scanners, can produce highly detailed anatomical images [1][2][3][4]. The increase in B 0 not only affects the number of spins available for excitation, but also the Larmor's frequency at which the spins enter into resonance [5][6][7]. This increase in the Larmor frequency and the number of spins for excitation also allows additional nuclei besides protons ( 1 H) to be used for acquiring MR images; this phenomenon is referred to as multi-nuclei MR imaging [8][9][10][11][12][13] or X-nuclei MRI.…”

Section: Introduction 1multinuclear Mrimentioning

confidence: 99%

Design of a Coplanar Interlayer Gapped Microstrips Arrangement for Multi-Nuclei (1H, 19F, 31P, and 23Na) Applications in 7T MRI

Hernández

2021

Applied Sciences

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Seven Tesla Magnetic Resonance (MR) systems can obtain high quality anatomical images using protons (1H) and can be used for multinuclear imaging and MR spectroscopy. These imaging modes can also obtain images and metabolic information using other nuclei, such as 19F, 31P, and 23Na. Here, we present an RF coil unit using a microstrip capable of resonating at four frequencies: 300 (1H), 280 (19F), 121 (31P), and 78 (23Na) MHz. The RF unit consists of a single feeding port and four lines that resonate and run a current at their respective frequency. We used the gapped microstrip concept to isolate each conducting line and interleaved the dielectric materials used for each line, thereby reducing the coupling between them. We also analyzed this design using electromagnetic (EM) simulations, and found that the quad tuned arrangement produced low coupling between adjacent current lines and achieved a uniform |B1| field in the z-y plane.

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Nuclear magnetic resonance in high magnetic field: Application to condensed matter physics

Cited by 21 publications

References 176 publications

Spatiotemporal Crossover between Low- and High-Temperature Dynamical Regimes in the Quantum Heisenberg Magnet

Spatiotemporal Crossover between Low- and High-Temperature Dynamical Regimes in the Quantum Heisenberg Magnet

Low-dimensional correlations under thermal fluctuations

Design of a Coplanar Interlayer Gapped Microstrips Arrangement for Multi-Nuclei (1H, 19F, 31P, and 23Na) Applications in 7T MRI

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