Year: 2005
Type: article
Abstract: Experimental studies of the antiferromagnetic (AF) heavy fermion metal YbRh2Si2 in a magnetic field B indicate the presence of a jump in the Hall coefficient at a magnetic-field tuned quantum state in the zero temperature limit. This quantum state occurs at B ≥ B c0 and induces the jump even though the change of the magnetic field at B = B c0 is infinitesimal. We investigated this by using the model of heavy electron liquid with the fermion condensate. Within this model, the jump takes place when the magnetic field reaches the critical value B c0 at which the ordering temperature T N(B = B c0) of the AF transition vanishes. We show that at B → B c0, this second order AF phase transition becomes the first order one, making the corresponding quantum and thermal critical fluctuations vanish at the jump. At T → 0 and B = B c0 the Grüneisen ratio as a function of the temperature T diverges. We demonstrate that both the divergence and the jump are determined by the specific low temperature behavior of the entropy $$S(T) \propto S_0 + a\sqrt T + bT$$ with S 0; a and b are temperature independent constants.
DOI: 10.1134/1.2121817
Authors: V. R. Shaginyan, K. G. Popov, S. A. Artamonov
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W1986140730