Hall-effect evolution across a heavy-fermion quantum critical point
| Autor: | Piers Coleman, Steffen Wirth, Philipp Gegenwart, T. Lühmann, Silke Paschen, O. Trovarelli, Qimiao Si, Frank Steglich, C. Geibel |
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| Rok vydání: | 2004 |
| Předmět: |
Quantum phase transition
Multidisciplinary Strongly Correlated Electrons (cond-mat.str-el) Condensed matter physics Chemistry Condensed Matter - Superconductivity FOS: Physical sciences Fermi surface Electronic structure Superconductivity (cond-mat.supr-con) Condensed Matter - Strongly Correlated Electrons Hall effect Quantum critical point Antiferromagnetism ddc:530 Condensed Matter::Strongly Correlated Electrons Ground state Absolute zero |
| Zdroj: | Nature. 432:881-885 |
| ISSN: | 1476-4687 0028-0836 |
| DOI: | 10.1038/nature03129 |
| Popis: | A quantum critical point (QCP) develops in a material at absolute zero when a new form of order smoothly emerges in its ground state. QCPs are of great current interest because of their singular ability to influence the finite temperature properties of materials. Recently, heavy-fermion metals have played a key role in the study of antiferromagnetic QCPs. To accommodate the heavy electrons, the Fermi surface of the heavy-fermion paramagnet is larger than that of an antiferromagnet. An important unsolved question concerns whether the Fermi surface transformation at the QCP develops gradually, as expected if the magnetism is of spin density wave (SDW) type, or suddenly as expected if the heavy electrons are abruptly localized by magnetism. Here we report measurements of the low-temperature Hall coefficient ($R_H$) - a measure of the Fermi surface volume - in the heavy-fermion metal YbRh2Si2 upon field-tuning it from an antiferromagnetic to a paramagnetic state. $R_H$ undergoes an increasingly rapid change near the QCP as the temperature is lowered, extrapolating to a sudden jump in the zero temperature limit. We interpret these results in terms of a collapse of the large Fermi surface and of the heavy-fermion state itself precisely at the QCP. Comment: 20 pages, 3 figures; to appear in Nature |
| Databáze: | OpenAIRE |
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