52 citations · 254 across the 10 of their papers we have counts for
10 papers
Direct observation of the Higgs amplitude mode in a two-dimensional quantum antiferromagnet near the quantum critical point
Tao Hong, Masashige Matsumoto, Yiming Qiu +12
Spontaneous symmetry-breaking quantum phase transitions play an essential role in condensed matter physics. The collective excitations in the broken-symmetry phase near the quantum…
Field induced spontaneous quasiparticle decay and renormalization of quasiparticle dispersion in a quantum antiferromagnet
Tao Hong, Y. Qiu, M. Matsumoto +7
The notion of a quasiparticle, such as a phonon, a roton, or a magnon, is used in modern condensed matter physics to describe an elementary collective excitation. The intrinsic zer…
Linked-cluster expansions for quantum magnets on the hypercubic lattice
K. Coester, D. G. Joshi, M. Vojta +1
For arbitrary space dimension we investigate the quantum phase transitions of two paradigmatic spin models defined on a hypercubic lattice, the coupled-dimer Heisenberg model a…
Emergence of a 2d macro-spin liquid in a highly frustrated 3d quantum magnet
Tycho S. Sikkenk, Kris Coester, Lars Fritz +1
The classical Ising model on the frustrated 3d swedenborgite lattice has disordered spin liquid ground states for all ratios of inter- and intra-planar couplings. Quantum fluctuati…
Optimizing linked cluster expansions by white graphs
K. Coester, K. P. Schmidt
We introduce a white graph expansion for the method of perturbative continuous unitary transformations when implemented as a linked cluster expansion. The essential idea behind an…
A generalized perspective on non-perturbative linked cluster expansions
K. Coester, S. Clever, F. Herbst +2
We identify a fundamental challenge for non-perturbative linked cluster expansions (NLCEs) resulting from the reduced symmetry on graphs, most importantly the breaking of translati…
Non-linear bond-operator theory and 1/d expansion for coupled-dimer magnets I: Paramagnetic phase
Darshan G. Joshi, Kris Coester, Kai P. Schmidt +1
For coupled-dimer Heisenberg magnets, a paradigm of magnetic quantum phase transitions, we develop a systematic expansion in 1/d, the inverse number of space dimensions. The expans…
Magnetic ordering induced by interladder coupling in the spin-1/2 Heisenberg two-leg ladder antiferromagnet CHNCuBr
Tao Hong, K. P. Schmidt, K. Coester +14
We present specific-heat and neutron-scattering results for the \emph{S}=1/2 quantum antiferromagnet (dimethylammonium)(3,5-dimethylpyridinium)CuBr. The material orders magneti…
Quantum disorder and local modes of the fully-frustrated transverse field Ising model on a diamond chain
K. Coester, W. Malitz, S. Fey +1
We investigate the transverse field Ising model on a diamond chain using series expansions about the high-field limit and exact diagonalizations. For the unfrustrated case we accur…
Disorder by disorder and flat bands in the kagome transverse field Ising model
M. Powalski, K. Coester, R. Moessner +1
We study the transverse field Ising model on a kagome and a triangular lattice using high-order series expansions about the high-field limit. For the triangular lattice our results…