Spectroscopic evidence for negative electronic compressibility in a quasi-three-dimensional spin-orbit correlated metal.
Negative compressibility is a sign of thermodynamic instability of open or non-equilibrium systems. In quantum materials consisting of multiple mutually coupled subsystems, the compressibility of one subsystem can be negative if it is countered by positive compressibility of the others. Manifestations of this effect have so far been limited to low-dimensional dilute electron systems. Here, we present evidence from angle-resolved photoemission spectroscopy (ARPES) for negative electronic compressibility (NEC) in the quasi-three-dimensional (3D) spin-orbit correlated metal (Sr1-xLax)3Ir2O7. Increased electron filling accompanies an anomalous decrease of the chemical potential, as indicated by the overall movement of the deep valence bands. Such anomaly, suggestive of NEC, is shown to be primarily driven by the lowering in energy of the conduction band as the correlated bandgap reduces. Our finding points to a distinct pathway towards an uncharted territory of NEC featuring bulk correlated metals with unique potential for applications in low-power nanoelectronics and novel metamaterials.
Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA.
Junfeng
J
He
Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA.
T
T
Hogan
Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA.
Thomas R
TR
Mion
Physics Department, Northeastern University, Boston, Massachusetts 02115, USA.
H
H
Hafiz
Stanford Synchrotron Radiation Lightsource &Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
Y
Y
He
Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
J D
JD
Denlinger
Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
S-K
SK
Mo
Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA.
C
C
Dhital
Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA.
X
X
Chen
Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA.
Qisen
Q
Lin
International Center for Quantum Materials, Peking University, Beijing 100871, China.
Y
Y
Zhang
Stanford Synchrotron Radiation Lightsource &Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
M
M
Hashimoto
Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA.
H
H
Pan
Stanford Synchrotron Radiation Lightsource &Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
D H
DH
Lu
Hiroshima Synchrotron Radiation Center, Hiroshima University, Hiroshima 739-0046, Japan.
M
M
Arita
Hiroshima Synchrotron Radiation Center, Hiroshima University, Hiroshima 739-0046, Japan.
K
K
Shimada
Physics Department, Northeastern University, Boston, Massachusetts 02115, USA.
R S
RS
Markiewicz
Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA.
Z
Z
Wang
Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA.
K
K
Kempa
Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA.
M J
MJ
Naughton
Physics Department, Northeastern University, Boston, Massachusetts 02115, USA.
A
A
Bansil
1] Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA [2] Materials Department, University of California Santa Barbara, Santa Barbara, California 93106, USA.
S D
SD
Wilson
Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA.
Rui-Hua
RH
He