scholarly journals Muon spin rotation and relaxation study on topological noncentrosymmetric superconductor PbTaSe2

2022 ◽  
Author(s):  
Zihao Zhu ◽  
Cheng Tan ◽  
Jian Zhang ◽  
Pabitra Kumar Biswas ◽  
A D Hillier ◽  
...  
Keyword(s):  
Energy Gap ◽  
Muon Spin ◽  
Three Dimensional ◽  
Transverse Field ◽  
Muon Spin Rotation ◽  
Zero Field ◽  
Noncentrosymmetric Superconductor ◽  
Topological Surface ◽  
Symmetry Protected ◽  
Topological Superconductivity

Abstract Topological superconductivity is an exotic phenomenon due to the symmetry-protected topological surface state, in which a quantum system has an energy gap in the bulk but supports gapless excitations conned to its boundary. Symmetries including central and time-reversal, along with their relations with topology, are crucial for topological superconductivity. We report muon spin relaxation/rotation (μSR) experiments on a topological noncentrosymmetric superconductor PbTaSe2 to study its TRS and gap symmetry. Zero-field μSR experiments indicate the absence of internal magnetic eld in the superconducting state, consistent with previous μSR results. Furthermore, transverse-field μSR measurements reveals that the superconducting gap of PbTaSe2 is an isotropic three-dimensional fully-gapped single-band. The fully-gapped results can help understand the pairing mechanism and further classify the topological superconductivity in this system.

A magnetic origin of cuprate superconductivity? A MaxEnt-μSR view

2015 ◽  
Vol 29 (25n26) ◽  
pp. 1542026 ◽  
Author(s):  
C. Boekema ◽  
F. Owens ◽  
A. Love ◽  
Z. Li ◽  
P. Sakkaris ◽  
...  
Keyword(s):  
Muon Spin ◽  
Transverse Field ◽  
Muon Spin Rotation ◽  
Zero Field ◽  
Text Data ◽  
Fundamental Physics ◽  
Site Search ◽  
Cuprate Superconductivity ◽  
Magnetic Origin ◽  
Text Signals

The fundamental physics of cuprate superconductivity is still much deliberated after three decades of research. In contrast to phononic or polaronic roots, some major theories promote a magnetic origin. In this perspective, we review cuprate magnetism, as probed by muon-spin-rotation [Formula: see text] in [Formula: see text] (RBCO), [Formula: see text] (Bi2212) and [Formula: see text] (Tl2223). Site-search RBCO studies show that muons localize and probe in locations away from the superconducting CuO2 planes. Maximum entropy (MaxEnt, ME) analysis of transverse field [Formula: see text] data of [Formula: see text] (GdBCO) indicates that the muon probes in an undisturbed insulating environment, allowing [Formula: see text] to detect (weak) magnetic features in these cuprates. Concerning Varma’s predicted loop currents, MaxEnt has shown weak [Formula: see text] signals for GdBCO in zero field above and below the critical temperature, [Formula: see text]; these are near the predicted [Formula: see text] Oe. Concerning Zhang’s predicted antiferromagnetism (AF) connected to the vortex cores, we have observed Lorentzian relaxation of cuprate vortex signals below half [Formula: see text], consistent with AF-broadening effects. For both Bi2212 and Tl2223, Lorentzians describe the [Formula: see text] vortex signals much better below [Formula: see text] than Gaussians, indicating that extra AF fields occur near and in the vortex cores. In sum, both our MaxEnt-[Formula: see text] (ME-[Formula: see text]) studies point toward magnetic roots of cuprate superconductivity.

scholarly journals On the Robustness of the MnSi Magnetic Structure Determined by Muon Spin Rotation

2018 ◽  
Vol 2 (3) ◽  
pp. 19 ◽  
Author(s):  
Pierre Dalmas de Réotier ◽  
Alain Yaouanc ◽  
Alex Amato ◽  
Alexander Maisuradze ◽  
Daniel Andreica ◽  
...  
Keyword(s):  
Magnetic Structure ◽  
Muon Spin ◽  
Transverse Field ◽  
Spin Rotation ◽  
Muon Spin Rotation ◽  
Zero Field ◽  
Magnetic Structures ◽  
Wide Range ◽  
Distribution Parameters ◽  
Manganese Silicide

Muon spin rotation ( μ SR) spectra recorded for manganese silicide MnSi and interpreted in terms of a quantitative analysis constrained by symmetry arguments were recently published. The magnetic structures of MnSi in zero-field at low temperature and in the conical phase near the magnetic phase transition were shown to substantially deviate from the expected helical and conical structures. Here, we present material backing the previous results obtained in zero-field. First, from simulations of the field distributions experienced by the muons as a function of relevant parameters, we confirm the uniqueness of the initial interpretation and illustrate the remarkable complementarity of neutron scattering and μ SR for the MnSi magnetic structure determination. Second, we present the result of a μ SR experiment performed on MnSi crystallites grown in a Zn-flux and compare it with the previous data recorded with a crystal obtained from Czochralski pulling. We find the magnetic structure for the two types of crystals to be identical within experimental uncertainties. We finally address the question of a possible muon-induced effect by presenting transverse field μ SR spectra recorded in a wide range of temperature and field intensity. The field distribution parameters perfectly scale with the macroscopic magnetization, ruling out a muon-induced effect.

MUON SPIN ROTATION IN SR2YRU1-UCUUO6

1999 ◽  
Vol 13 (29n31) ◽  
pp. 3670-3677 ◽  
Author(s):  
D. R. HARSHMAN ◽  
H. A. BLACKSTEAD ◽  
W. J. KOSSLER ◽  
A. J. GREER ◽  
C. E. STRONACH ◽  
...  
Keyword(s):  
Field Data ◽  
Muon Spin ◽  
Magnetic Moments ◽  
Transverse Field ◽  
Sudden Onset ◽  
Spin Rotation ◽  
Muon Spin Rotation ◽  
Zero Field ◽  
Slow Dynamic ◽  
Oxygen Ions

The magnetic and superconducting behaviors of sintered Sr 2 YRu 1-u Cu u O 6 (for u=0.05, 0.10, 0.15) were probed using transverse- and zero-field muon spin rotation (μ+ SR). In general, positive muons are attracted to oxygen ions in the high-T c oxides, and so, Sr 2 YRu 1-u Cu u O 6 should (and does) present two types of μ+ sites, those associated with the oxygen in the YRuO 4 layers and those associated with the SrO-layer oxygen. The tranverse- and zero-field data for all three stoichiometries u exhibit a sudden onset of magnetic structure at TN~30 K, with a static local field of ~3 kG. This transition is marked by a dramatic increase in the relaxation rate as the temperature decreases below TN, corresponding to an increased static disordering of the magnetic moments. Above TN no static fields are observed. Instead the data exhibit a slow dynamic depolarization, presumably due to the rapid fluctuation of paramagnetic moments. Both transverse- and zero-field data also indicate a smaller second component (~10%) which we associate with the SrO layer, exhibiting superconducting behavior in transverse field with an observed T c ≈TN~30 K.

scholarly journals Unsplit superconducting and time reversal symmetry breaking transitions in Sr2RuO4 under hydrostatic pressure and disorder

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Vadim Grinenko ◽  
Debarchan Das ◽  
Ritu Gupta ◽  
Bastian Zinkl ◽  
Naoki Kikugawa ◽  
...  
Keyword(s):  
Hydrostatic Pressure ◽  
Symmetry Breaking ◽  
Time Reversal ◽  
Order Parameter ◽  
Muon Spin Rotation ◽  
Horizontal Line ◽  
Time Reversal Symmetry ◽  
Zero Field ◽  
Symmetry Protected ◽  
Line Node

AbstractThere is considerable evidence that the superconducting state of Sr2RuO4 breaks time reversal symmetry. In the experiments showing time reversal symmetry breaking, its onset temperature, TTRSB, is generally found to match the critical temperature, Tc, within resolution. In combination with evidence for even parity, this result has led to consideration of a dxz ± idyz order parameter. The degeneracy of the two components of this order parameter is protected by symmetry, yielding TTRSB = Tc, but it has a hard-to-explain horizontal line node at kz = 0. Therefore, s ± id and d ± ig order parameters are also under consideration. These avoid the horizontal line node, but require tuning to obtain TTRSB ≈ Tc. To obtain evidence distinguishing these two possible scenarios (of symmetry-protected versus accidental degeneracy), we employ zero-field muon spin rotation/relaxation to study pure Sr2RuO4 under hydrostatic pressure, and Sr1.98La0.02RuO4 at zero pressure. Both hydrostatic pressure and La substitution alter Tc without lifting the tetragonal lattice symmetry, so if the degeneracy is symmetry-protected, TTRSB should track changes in Tc, while if it is accidental, these transition temperatures should generally separate. We observe TTRSB to track Tc, supporting the hypothesis of dxz ± idyz order.

Zero-Field Muon Spin Rotation Studies in (TMTSF) 2 PF 6

1991 ◽  
Vol 15 (5) ◽  
pp. 547-552 ◽  
Author(s):  
L. P Le ◽  
G. M Luke ◽  
B. J Sternlieb ◽  
W. D Wu ◽  
Y. J Uemura ◽  
...  
Keyword(s):  
Muon Spin ◽  
Spin Rotation ◽  
Muon Spin Rotation ◽  
Zero Field

scholarly journals Two-gap superconductivity in Lu2Fe3Si5: A transverse-field muon spin rotation study

2011 ◽  
Vol 83 (5) ◽  
Author(s):  
P. K. Biswas ◽  
G. Balakrishnan ◽  
D. McK. Paul ◽  
M. R. Lees ◽  
A. D. Hillier
Keyword(s):  
Muon Spin ◽  
Transverse Field ◽  
Spin Rotation ◽  
Muon Spin Rotation ◽  
Rotation Study

scholarly journals Transverse field muon-spin rotation signature of the skyrmion-lattice phase inCu2OSeO3

2015 ◽  
Vol 91 (22) ◽  
Author(s):  
T. Lancaster ◽  
R. C. Williams ◽  
I. O. Thomas ◽  
F. Xiao ◽  
F. L. Pratt ◽  
...  
Keyword(s):  
Muon Spin ◽  
Transverse Field ◽  
Spin Rotation ◽  
Muon Spin Rotation

scholarly journals Enhancement of Electron Movement in Cytochrome c protein with Water Hydration

2017 ◽  
pp. 20-23
Author(s):  
Amba Datt Pant
Keyword(s):  
Relative Humidity ◽  
Cytochrome C ◽  
Room Temperature ◽  
Muon Spin ◽  
Three Dimensional ◽  
Spin Rotation ◽  
Muon Spin Rotation ◽  
Temperature Analysis ◽  
C Protein ◽  
Dimensional Diffusion

Muon spin rotation and relaxation (µSR) measurements have been carried out on oxidized form of cytochrome c protein to understand the relation of electron transfer with water hydration at room temperature. Analysis of µSR data following the Risch-Kehr theory shows that intra- and inter-chain electron movement in the protein enhanced significantly. The three-dimensional diffusion of electron in wet sample (20% relative humidity) is increased around 75% with respect to that in dry sample (5% relative humidity).The Himalayan Physics Vol. 6 & 7, April 2017 (20-23)

Radical addition to ruthenocene at low temperatures: characterization of ruthenocenyl radicals by μSR spectroscopy

2018 ◽  
Vol 96 (3) ◽  
pp. 358-362 ◽  
Author(s):  
Iain McKenzie
Keyword(s):  
Dft Calculations ◽  
Spin Relaxation ◽  
Muon Spin ◽  
Transverse Field ◽  
Relaxation Mechanism ◽  
Coupling Constants ◽  
Muon Spin Rotation ◽  
Electron Spin Relaxation ◽  
Spin Resonance ◽  
Experimental Values

The radicals formed by muonium (Mu) addition to ruthenocene at low temperature (4–200 K) have been characterized by transverse field muon spin rotation (TF-μSR) and avoided level crossing muon spin resonance (ALC-μSR) spectroscopy. The structures of the muoniated radicals have been identified by comparing the experimentally measured muon hyperfine coupling constants with values obtained from DFT calculations (UB3LYP/DGDZVP). Mu addition was observed at the ruthenium and at the cyclopentadiene (Cp) rings, both from the exterior and interior directions. Closer agreement between the DFT calculations and the experimental values are obtained if it is assumed the structures of the Mu adducts of the Cp rings are distorted due to interactions with neighbouring molecules. Changes in the ALC-μSR spectra with temperature indicated that the electron spin relaxation rate of the Cp adducts increases with temperature; however, the specific spin relaxation mechanism is unknown.

scholarly journals Three-Dimensional Topological States of Phonons with Tunable Pseudospin Physics

Research ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Yizhou Liu ◽  
Yong Xu ◽  
Wenhui Duan
Keyword(s):  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Surface States ◽  
Phonon Transport ◽  
Efficient Control ◽  
Topological States ◽  
Topological Surface ◽  
Symmetry Protected ◽  
Energy Information ◽  
Crystalline Symmetry

Efficient control of phonons is crucial to energy-information technology, but limited by the lacking of tunable degrees of freedom like charge or spin. Here we suggest to utilize crystalline symmetry-protected pseudospins as new quantum degrees of freedom to manipulate phonons. Remarkably, we reveal a duality between phonon pseudospins and electron spins by presenting Kramers-like degeneracy and pseudospin counterparts of spin-orbit coupling, which lays the foundation for “pseudospin phononics”. Furthermore, we report two types of three-dimensional phononic topological insulators, which give topologically protected, gapless surface states with linear and quadratic band degeneracies, respectively. These topological surface states display unconventional phonon transport behaviors attributed to the unique pseudospin-momentum locking, which are useful for phononic circuits, transistors, antennas, etc. The emerging pseudospin physics offers new opportunities to develop future phononics.

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