High Magnetic Field Phases of the (TMTSF)2X (X = CLO4, PF6) Charge Transfer Complexes

1989 ◽  
Vol 173 ◽  
Author(s):  
J. S. Brooks ◽  
N. A. Fortune ◽  
P. M. Chaikin ◽  
L. Y. Chiang ◽  
G. Montambaux ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Charge Transfer ◽  
Magnetic Fields ◽  
Specific Heat ◽  
Low Temperatures ◽  
Density Wave ◽  
Spin Density Wave ◽  
Metallic State ◽  
Low Field ◽  
Fast Oscillations

ABSTRACTThe purpose of this talk is to discuss the physical properties of the (TMTSF)2X charge transfer salts in high magnetic fields. This class of materials is of great interest since the effective lower dimensionality and the various ground states are magnetic field dependent at low temperatures. At present, the so-called “standard model” provides a good theoretical description of the low field field induced spin density wave transitions (FISDW). However the reentrance from the last FISDW back to a high field metallic state, and the coexistence of “fast oscillations” in all measured properties, is yet to be accurately described theoretically. The emphasis of this paper is on recent specific heat results which have been obtained on (TMTSF)2ClO4 in magnetic fields as high as 30 T. Here we observe both the reentrant phase transition and the fast oscillations in the specific heat. A main conclusion we draw from our measurements is that the density of states in the reentrant phase is less than it is in the low field metallic state at low temperatures.

scholarly journals Linear magnetoresistance in the low-field limit in density-wave materials

2019 ◽  
Vol 116 (23) ◽  
pp. 11201-11206 ◽  
Author(s):  
Yejun Feng ◽  
Yishu Wang ◽  
D. M. Silevitch ◽  
J.-Q. Yan ◽  
Riki Kobayashi ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Low Temperature ◽  
Applied Field ◽  
Density Wave ◽  
Spin Density Wave ◽  
Field Limit ◽  
Fermi Surfaces ◽  
Low Field ◽  
Metallic Charge ◽  
Linear Magnetoresistance

The magnetoresistance (MR) of a material is typically insensitive to reversing the applied field direction and varies quadratically with magnetic field in the low-field limit. Quantum effects, unusual topological band structures, and inhomogeneities that lead to wandering current paths can induce a cross-over from quadratic to linear MR with increasing magnetic field. Here we explore a series of metallic charge- and spin-density-wave systems that exhibit extremely large positive linear MR. By contrast to other linear MR mechanisms, this effect remains robust down to miniscule magnetic fields of tens of Oersted at low temperature. We frame an explanation of this phenomenon in a semiclassical narrative for a broad category of materials with partially gapped Fermi surfaces due to density waves.

Low-Dimensional Critical Behaviors and Competition Between Order Parameters in the Organic Metal (Tmtsf)2ClO4

1989 ◽  
Vol 173 ◽  
Author(s):  
F. Pesty ◽  
P. Garoche ◽  
M. Heritier
Keyword(s):  
Magnetic Field ◽  
Thermal Conductivity ◽  
Specific Heat ◽  
High Field ◽  
Density Wave ◽  
Second Order ◽  
Metallic State ◽  
Transition Line ◽  
One Dimensional ◽  
Low Dimensional

ABSTRACTIn low-dimensional conductors, the instability of the metallic state can lead to the formation at low temperature of a spin density wave induced by the magnetic field (FISDW). The transition results from the complex interplay between the one dimensional instability of the electronic gas and the quantization of the magnetic field’s flux. This second-order phase-transition line has been investigated by measuring both specific heat and thermal conductivity along the c* direction. The mean-field jump and the gap value have been deduced respectively from the anomaly and the exponential decay of the electronic specific heat. The coupling strength λ has been evaluated, and the λ > 0.3 value indicates clearly a strong coupling behavior at high field. Below 8 teslas, the specific heat displays a double anomaly in relation with the competition between subphases. Above the second-order transition line, critical fluctuations are observed on both specific heat and lattice thermal conductivity. Along this line, one-dimensional fluctuations increase with increasing magnetic field. It is proposed that the very high field reentrance of the metal is to be related to enhancement of the 1D fluctuations.

Magnetic-field behavior of the spin-density-wave state in (TMTSF)2AsF6

1995 ◽  
Vol 52 (22) ◽  
pp. 15983-15991 ◽  
Author(s):  
J. L. Musfeldt ◽  
M. Poirier ◽  
P. Batail ◽  
C. Lenoir
Keyword(s):  
Magnetic Field ◽  
Spin Density ◽  
Density Wave ◽  
Spin Density Wave ◽  
Wave State ◽  
Field Behavior

COLLECTIVE FIELD THEORY TO MAGNETIC-FIELD-INDUCED SPIN-DENSITY-WAVE-STATE IN BECHGAARD SALTS, (TMTSF)2X

1993 ◽  
Vol 07 (19) ◽  
pp. 3415-3421 ◽  
Author(s):  
ALEXANDRE S. ROZHAVSKY
Keyword(s):  
Magnetic Field ◽  
Spin Density ◽  
Chemical Potential ◽  
Density Wave ◽  
Spin Density Wave ◽  
Hall Conductivity ◽  
Chiral Anomaly ◽  
Threshold Field ◽  
Wave State ◽  
Extended States

A field description of spin-density-wave (SDW) in a quasi-two-dimensional metal with open Fermi surface in magnetic field, is proposed. The SDW transition temperature, T c (H), and the Hall conductivity σxy, are calculated. The dependence T c (H) is found to be different from that of the Bardeen-Cooper-Schrieffer model, in particular, a threshold field, H c , found its natural explanation. It is proved that the quantized Hall conductivity arises from the chiral anomaly terms in the effective action provided there is pinning of chemical potential in the gap of extended states.

High-field magnetoresistance of the Bechgaard salt (TMTSF)2AsF6:Fast oscillations and spin-density-wave transition

1997 ◽  
Vol 55 (5) ◽  
pp. 3024-3027 ◽  
Author(s):  
Jean Pierre Ulmet ◽  
Abdelhadi Narjis ◽  
Michael J. Naughton ◽  
Jean Marc Fabre
Keyword(s):  
Spin Density ◽  
High Field ◽  
Density Wave ◽  
Spin Density Wave ◽  
Bechgaard Salt ◽  
Fast Oscillations

High magnetic field NMR investigation of the spin density wave phase of TMTSF2PF6

2002 ◽  
Vol 12 (9) ◽  
pp. 389-389
Author(s):  
W. G. Clark ◽  
F. Zamborsky ◽  
B. Alavi ◽  
P. Vonlanthen ◽  
W. Moulton ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Spin Density ◽  
Density Wave ◽  
Spin Density Wave ◽  
Proton Relaxation ◽  
High Magnetic Fields ◽  
Organic Conductor ◽  
First Order ◽  
The Magnetic Field ◽  
Very High

We report proton NMR measurements of the effect of very high magnetic fields up to 44.7 T (1.9 GHz) on the spin density wave (SDW) transition of the organic conductor TMTSF2PF6. Up to 1.8 GHz, no effect of critical slowing close to the transition is seen on the proton relaxation rate (1/T1), which is determined by the SDW fluctuations associated with the phase transition at the NMR frequency. Thus, the correlation time for such fluctuations is less than $1O^{-10}$s. A possible explanation for the absence of longer correlation times is that the transition is weakly first order, so that the full critical divergence is never achieved. The measurements also show a dependence of the transition temperature on the orientation of the magnetic field and a quadratic dependence on its magnitude that agrees with earlier transport measurements at lower fields. The UCLA part of this work was supported by NSF Grant DMR-0072524.

scholarly journals URu2Si2 under intense magnetic fields: From hidden order to spin-density wave

2018 ◽  
Vol 536 ◽  
pp. 457-460 ◽  
Author(s):  
W. Knafo ◽  
D. Aoki ◽  
G.W. Scheerer ◽  
F. Duc ◽  
F. Bourdarot ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Spin Density ◽  
Density Wave ◽  
Spin Density Wave ◽  
Hidden Order
Sign in / Sign up

Export Citation Format

Share Document