2005 APS March Meeting
Monday–Friday, March 21–25, 2005;
Los Angeles, CA
Session A2: Quantum Criticality of Strongly Correlated Metals
8:00 AM–10:24 AM,
Monday, March 21, 2005
LACC
Room: 151
Sponsoring
Unit:
DCMP
Chair: Brian Maple, University of California-San Diego
Abstract ID: BAPS.2005.MAR.A2.1
Abstract: A2.00001 : Hall effect indicates destruction of large Fermi surface at a heavy-fermion quantum critical point
8:00 AM–8:36 AM
Preview Abstract
Abstract
Author:
Silke Paschen
(Max Planck Institute for Chemical Physics of Solids, Dresden, Germany)
Quantum critical points (QCPs) -– phase transitions at absolute
zero in temperature -- 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 [1]. 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
type [2], or suddenly as expected if the heavy electrons are
abruptly localized by magnetism [3]. Here we report
measurements of the low-temperature Hall coefficient ($R_H$) --
a measure of the Fermi surface volume -- in the heavy-fermion
metal YbRh$_2$Si$_2$ 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
[4].\\[0.2cm]
[1] R.~M.~Martin, {\em {Phys.\ Rev.\ Lett.}}{ \bf 48}, {362--
365} (1982);
P. ~Fulde, {in \em {Narrow-Band Phenomena -- Influence of
Electrons with both
Band and Localized Character}} (ed.\ Fuggle, J.~C.) 27--29
(Plenum Press, New
York, 1988); M.~Oshikawa, {\em {Phys.\ Rev.\ Lett.}}{ \bf 84},
3370--3373 (2000).\\[0.2cm]
[2] J.~A.~Hertz, {\em {Phys.\ Rev.\ B}}{ \bf 14}, 1165--1184
(1976); A.~J.~Millis, {\em {Phys.\ Rev.\ B}}{ \bf 48}, 7183--
7196 (1993).\\[0.2cm]
[3] A.~Schr\"{o}der \emph{et~al.}, {\em {Nature}}{ \bf 407}, 351-
-355 (2000);
P.~Coleman \emph{et~al.}, {\em {J.\ Phys.: Condens.\ Matter}}{
\bf 13}, R723--R738 (2001); Q.~Si \emph{et~al.}, {\em Nature}{
\bf 413}, 804--808 (2001).\\[0.2cm]
[4] S.~Paschen \emph{et~al.}, to appear in {\em Nature}.\\[0.2cm]
In collaboration with: T.~L{\"u}hmann, S.~Wirth, P.~Gegenwart,
O.~Trovarelli, C.~Geibel, F.~Steglich, P.~Coleman, and Q.~Si.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2005.MAR.A2.1