Fermi Surface Structure and Isotropic Stability of Fulde-Ferrell-Larkin-Ovchinnikov Phase in Layered Organic Superconductor β″-(BEDT-TTF)2SF5CH2CF2SO3

The Fermi surface structure of a layered organic superconductor β″-(BEDT-TTF)2SF5CH2CF2SO3 was determined by angular-dependent magnetoresistance oscillations measurements and band-structure calculations. This salt was found to have two small pockets with the same area: a deformed square hole pocket and an elliptic electron pocket. Characteristic corrugations in the field dependence of the interlayer resistance in the superconducting phase were observed at any in-plane field directions. The features were ascribed to the commensurability (CM) effect between the Josephson vortex lattice and the periodic nodal structure of the superconducting gap in the Fulde–Ferrell–Larkin–Ovchinnikov (FFLO) phase. The CM effect was observed in a similar field region for various in-plane field directions, in spite of the anisotropic nature of the Fermi surface. The results clearly showed that the FFLO phase stability is insensitive to the in-plane field directions.

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Characterization of the Fermi surface of the organic superconductor - by measurements of Shubnikov-de Haas and angle-dependent magnetoresistance oscillations and by electronic band-structure calculations

The European Physical Journal B ◽

10.1007/s100510050185 ◽

1998 ◽

Vol 1 (3) ◽

pp. 295-300 ◽

Cited By ~ 38

Author(s):

D. Beckmann ◽

S. Wanka ◽

J. Wosnitza ◽

J.A. Schlueter ◽

J.M. Williams ◽

...

Keyword(s):

Band Structure ◽

Fermi Surface ◽

Electronic Band Structure ◽

Organic Superconductor ◽

Electronic Band ◽

Band Structure Calculations ◽

Magnetoresistance Oscillations ◽

Structure Calculations

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Angular magnetoresistance oscillations and the shape of the Fermi surface in ?(ET)2IBr2

Journal de Physique I ◽

10.1051/jp1:1992125 ◽

1992 ◽

Vol 2 (1) ◽

pp. 89-99 ◽

Cited By ~ 88

Author(s):

M. V. Kartsovnik ◽

V. N. Laukhin ◽

S. I. Pesotskii ◽

I. F. Schegolev ◽

V. M. Yakovenko

Keyword(s):

Fermi Surface ◽

Magnetoresistance Oscillations

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Fermi surface of the skutterudite CoSb3 : Quantum oscillations and band-structure calculations

Physical Review B ◽

10.1103/physrevb.103.085133 ◽

2021 ◽

Vol 103 (8) ◽

Author(s):

M. Naumann ◽

P. Mokhtari ◽

Z. Medvecka ◽

F. Arnold ◽

M. Pillaca ◽

...

Keyword(s):

Band Structure ◽

Fermi Surface ◽

Quantum Oscillations ◽

Band Structure Calculations ◽

Structure Calculations

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The de Haas–van Alphen effect in alkali metals

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1964.0169 ◽

1964 ◽

Vol 281 (1384) ◽

pp. 62-91 ◽

Cited By ~ 206

Keyword(s):

Fermi Surface ◽

Field Dependence ◽

Alkali Metals ◽

Spherical Shape ◽

Orientation Dependence ◽

Sodium Potassium ◽

Fermi Surfaces ◽

Fixed Orientation ◽

Absolute Amplitude ◽

Structure Calculations

A new method for studying the de Haas–van Alphen effect in steady magnetic fields has been developed in which the field is modulated at frequency ω and a signal at frequency 2 ω is generated in a pick-up coil round the specimen because of the non-linear field dependence of magnetization. The rectified 2 ω signal is proportional to d 2 M /dH 2 and so shows de Haas–van Alphen oscillations either when H is varied for fixed orientation or when the orientation is varied in fixed H if the Fermi surface is anisotropic. Because the phase of oscillation is very high (of order 10 4 π ) even very slight anisotropy will produce a few oscillations when the orientation is varied and the method is therefore particularly sensitive for studying very nearly spherical Fermi surfaces. From the oscillations with H , values of the frequency F were found for sodium, potassium, rubidium and caesium which were close to those predicted for a free-electron sphere containing 1 electron per atom, though some small systematic deviations of order ½ % were observed which may be significant. From detailed study of the oscillations produced by rotation of single crystals in fixed H it was found possible to describe the orientation dependence of F (proportional to the area of cross-section of the Fermi surface) for potassium and rubidium consistently by a series of cubic harmonics and hence to deduce the small departures of the Fermi surfaces from spherical shape. The deviations from a sphere were found to be of the order of 1 part in 10 3 for potassium and a little less than 1 part in 10 2 for rubidium; these deviations are compared with those predicted by band structure calculations. Preliminary results for sodium suggest that it is appreciably less anisotropic than potassium. Some results are also reported on the temperature and field dependence and the absolute amplitude of the de Haas-van Alphen effect, and it is also shown how the effect can be used to measure very small variations of field with position.

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Experimental uniaxial stress and strain derivatives of the Fermi surface of rhenium

Canadian Journal of Physics ◽

10.1139/p80-158 ◽

1980 ◽

Vol 58 (8) ◽

pp. 1191-1199 ◽

Cited By ~ 4

Author(s):

E. Fawcett ◽

F. W. Holroyd ◽

J. M. Perz

Keyword(s):

Fermi Surface ◽

Uniaxial Stress ◽

Stress And Strain ◽

Strong Anisotropy ◽

Quantum Oscillations ◽

Band Structure Calculations ◽

Landau Quantum ◽

Derivatives Of ◽

Structure Calculations ◽

The Magnetic Field

The derivatives of the areas of extremal orbits on all the small sheets of the Fermi surface of rhenium, with respect to stress and strain along the hexad axis, have been determined from simultaneous measurements of Landau quantum oscillations in magnetostriction and torque, and also in sound velocity and torque. Strong anisotropy is observed in the stress derivatives of orbits in zones five and six as the direction of the magnetic field defining the normal to the orbit is varied; the anisotropy is most pronounced for orbits which come close to the line of degeneracy AL on the hexagonal Brillouin zone face. The derivatives of the small void in zone eight are found to be very large; this is consistent with the results of band structure calculations which show that this feature of the Fermi surface is very sensitive to small changes in the Fermi energy. Cyclotron effective masses for a number of orbits on the void have also been measured.

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