Acoustic De Haas-van Alphen Effect Research Articles

Ultrasonic investigation of Fermi surface

The acoustic de Haas-van Alphen effect of the quantum oscillation in the elastic constant is an excellent probe to examine the electron-lattice interaction of the itinerant electron system. In this paper we show the cryomagnetic systems for low-temperature ultrasonic measurements and the results of metallic compound LaB 6 and semimetallic LaAs.

Acoustic de Haas-van Alphen effect to determine the electron-lattice coupling

The previous theory of the acoustic de Haas-van Alphen effect [J. Phys. Soc. Japan 62 (1993) 4352] is extended to take account of the change of the electronic density of states under the periodic boundary condition, and to study the electron system with a most general type of electron-lattice coupling.

Acoustic de Haas-van Alphen effect in LaAs

Acoustic de Haas-van Alphen effect of a semi-metallic compound LaAs has been investigated. The electron α Fermi surfaces and the hole β, γ surfaces in LaAs have been observed. The carrier number of LaAs was n = 0.0024 per La atom. The oscillation intensity of the longitudinal C 11 mode revealed enhanced values |g ii| ≊ 8–16 of the electron-strain coupling constant α and β surfaces in LaAs.

Acoustic de Haas-van Alphen effect and electron-strain interaction in f-electron systems

Investigations of the acoustic de Haas-van Alphen effect in f-electron systems have been performed. The electron-strain interaction of a series of rare earth monopnictides and the rotation effect of LaB 6 has been presented.

Cryomagnetic system for the acoustic de Haas-van Alphen measurement

A 3He evaporating cryostat and a 3He- 4He dilution refrigerator have been developed for measurements of the acoustic de Haas-van Alphen effect in f-electron compounds. Sample-rotating devices in the cryomagnetic systems were developed. High-frequency coaxial lines were fabricated in the dilution refrigerator.

Acoustic de Haas-van Alphen effect in LaB 6 and CeB 6

The acoustic de Haas-van Alphen effect of the heavy fermion compound CeB 6 and the reference system LaB 6 has been measured. A pronounced enhancement of the electron-strain interaction in particular regions on the Fermi surface of LaB 6 has been found. The spin splitting of the electron pocket in CeB 6 has been discussed.

Two-Circle Goniometer for Measurement of Acoustic de Haas-van Alphen Effect

A sample-orienting device with a two-circle goniometer has been developed. This permits continuous rotation of either of the two perpendicular axes in a magnetic field and provids accurate measurement of the acoustic de Haas-van Alphen effect.

Dilution refrigerator for measurement of the acoustic de Haas - van Alphen effect

A dilution refrigerator with a cooling power of 500 μW/100 mK combined with a superconducting magnet of up to 13.5 T has been developed for measurement of the acoustic de Haas-van Alphen effect for heavy fermion compounds. A sample was immersed in a liquid 3He– 4He mixture in the tail of the mixing chamber. A one-circle goniometer with a spiral gear to change the sample orientation with respect to the magnetic field was driven by a superconducting stepping motor in the mixing chamber. The ultrasonic pulse was transmitted through the high frequency CuNi coaxial lines with an electric impedance of 50 Ω.