Abstract
We consider the behavior of the Grüneisen parameter, the ratio between thermal expansion and specific heat, at pressure-tuned infinite-randomness quantum-critical points and in the associated quantum Griffiths phases. We find that the Grüneisen parameter diverges as ln (T0 /T) with vanishing temperature T in the quantum Griffiths phases. at the infinite-randomness critical point itself, the Grüneisen parameter behaves as [ln (T0 /T)]1+1/ (νψ) where ν and ψ are the correlation length and tunneling exponents. Analogous results hold for the magnetocaloric effect at magnetic-field-tuned transitions. We contrast clean and dirty systems, we discuss subtle differences between Ising and Heisenberg symmetries, and we relate our findings to recent experiments on CePd1-xRhx.
Recommended Citation
T. Vojta, "Thermal Expansion and Grüneisen Parameter in Quantum Griffiths Phases," Physical Review B - Condensed Matter and Materials Physics., American Physical Society (APS), Jul 2009.
The definitive version is available at https://doi.org/10.1103/PhysRevB.80.041101
Department(s)
Physics
Sponsor(s)
National Science Foundation (U.S.)
Research Corporation
University of Missouri Research Board
Keywords and Phrases
Grüneisen Parameter; Quantum Griffiths Phases; Thermal Expansion
Document Type
Article - Journal
Document Version
Final Version
File Type
text
Language(s)
English
Rights
© 2009 American Physical Society (APS), All rights reserved.
Publication Date
01 Jul 2009
