94 citations · 890 across the 35 of their papers we have counts for
24 papers · 1 filter
Universal dynamics of a pair condensate
Qing Huang, Hao Zhang, Yiqing Hao +10
Pair condensates appear in multiple branches of physics, always introducing exotic phenomena. The pair condensate in quantum magnetism is the spin nematic, whose static (quadrupola…
Electronic Raman scattering of antiferromagnetic excitonic insulators
Hidemaro Suwa, Shang-Shun Zhang, Cristian D. Batista
The excitonic insulator, a quantum mechanical state arising from exciton condensation, was proposed theoretically many years ago but has yet to be experimentally confirmed. The dis…
Tetrahedral triple-Q magnetic ordering and large spontaneous Hall conductivity in the metallic triangular antiferromagnet Co1/3TaS2
Pyeongjae Park, Woonghee Cho, Chaebin Kim +14
The triangular lattice antiferromagnet (TLAF) has been the standard paradigm of frustrated magnetism for several decades. The most common magnetic ordering in insulating TLAFs is t…
Free energy and specific heat near a quantum critical point of a metal
Shang-Shun Zhang, Erez Berg, Andrey V. Chubukov
We analyze free energy and specific heat for fermions interacting with gapless bosons at a quantum-critical point (QCP) in a metal. We use the Luttinger-Ward-Eliashberg formula for…
BCS-BEC Crossover of Triplet Exciton Condensation in Bilayer Systems
Hidemaro Suwa, Shang-Shun Zhang, Cristian D. Batista
We study the BCS-BEC crossover phenomenon of triplet exciton condensation using a half-filled bilayer Hubbard model. We calculate the dynamical spin structure factor and the excito…
Odd frequency pairing in a quantum critical metal
Yi-Ming Wu, Shang-Shun Zhang, Artem Abanov +1
We analyze a possibility for odd-frequency pairing near a quantum critical point(QCP) in a metal. We consider a model with dynamical pairing interaction (the…
Evidence of Two-Spinon Bound States in the Magnetic Spectrum of BaCoSbO
E. A. Ghioldi, Shang-Shun Zhang, Yoshitomo Kamiya +3
Recent inelastic neutron scattering (INS) experiments of the triangular antiferromagnet BaCoSbO revealed strong deviations from semiclassical theories. We demonstrate t…
Witnessing quantum criticality and entanglement in the triangular antiferromagnet KYbSe
A. O. Scheie, E. A. Ghioldi, J. Xing +20
The Heisenberg triangular lattice quantum spin liquid and the phase transitions to nearby magnetic orders have received much theoretical attention, but clear experimental manifesta…
Schwinger boson theory of ordered magnets
Shang-Shun Zhang, E. A. Ghioldi, L. O. Manuel +2
The Schwinger boson theory provides a natural path for treating quantum spin systems with large quantum fluctuations. In contrast to semi-classical treatments, this theory allows u…
Instabilities of heavy magnons in an anisotropic magnet
Xiaojian Bai, Shang-Shun Zhang, Hao Zhang +5
The search for new elementary particles is one of the most basic pursuits in physics, spanning from subatomic physics to quantum materials. Magnons are the ubiquitous elementary qu…
Theory of the Kitaev model in a [111] magnetic field
Shang-Shun Zhang, Gábor B. Halász, Cristian D. Batista
Recent numerical studies indicate that the antiferromagnetic Kitaev honeycomb lattice model undergoes a magnetic-field-induced quantum phase transition into a new spin-liquid phase…
Exciton condensation in bilayer spin-orbit insulator
Hidemaro Suwa, Shang-Shun Zhang, Cristian D. Batista
We investigate the nature of the magnetic excitations of a bilayer single-orbital Hubbard model in the intermediate-coupling regime. This model exhibits a quantum phase transition…
Variational study of the Kitaev-Heisenberg-Gamma model
Shang-Shun Zhang, Gábor B. Halász, Wei Zhu +1
We compute the low-energy excitation spectrum and the dynamical spin structure factor of the Kitaev-Heisenberg-Gamma model through a variational approach based on the exact fractio…
Observation of 4- and 6-magnon bound-states in the spin-anisotropic frustrated antiferromagnet FeI
Anaëlle Legros, Shang-Shun Zhang, Xiaojian Bai +6
Spin-waves e.g. magnons are the conventional elementary excitations of ordered magnets. However, other possibilities exist. For instance, magnon bound-states can arise due to attra…
Hybridized quadrupolar excitations in the spin-anisotropic frustrated magnet FeI2
Xiaojian Bai, Shang-Shun Zhang, Zhiling Dun +8
Magnetic order is usually associated with well-defined magnon excitations. Exotic magnetic fluctuations with fractional, topological or multipolar character, have been proposed for…
Magnetic-field-induced tunability of spin Hamiltonians: Resonances and Efimov states in YbTiO
Yasuyuki Kato, Shang-Shun Zhang, Yusuke Nishida +1
Universality is a powerful concept that arises from the divergence of a characteristic length scale. For condensed matter systems, this length scale is typically the correlation le…
Toward Kitaev's sixteenfold way in a honeycomb lattice model
Shang-Shun Zhang, Cristian D. Batista, Gábor B. Halász
Kitaev's sixteenfold way is a classification of exotic topological orders in which gauge theory is coupled to Majorana fermions of Chern number . The distinc…
Real space Berry curvature of itinerant electron systems with spin-orbit interaction
Shang-Shun Zhang, Hiroaki Ishizuka, Hao Zhang +2
By considering an extended double-exchange model with spin-orbit coupling (SOC), we derive a general form of the Berry phase that electrons pick up when moving around a closed…
Large- limit of the large- theory for the triangular antiferromagnet
Shang-Shun Zhang, E. A. Ghioldi, Yoshitomo Kamiya +3
Large- and large- theories (spin value and spinor component number ) are complementary, and sometimes conflicting, approaches to quantum magnetism. While large- spi…
Vison Crystals in an Extended Kitaev Model on the Honeycomb Lattice
Shang-Shun Zhang, Zhentao Wang, Gábor B. Halász +1
We introduce an extension of the Kitaev honeycomb model by including four-spin interactions that preserve the local gauge structure and hence the integrability of the original mode…
Large magnetic thermal conductivity induced by frustration in low-dimensional quantum magnets
Jan Stolpp, Shang-Shun Zhang, Fabian Heidrich-Meisner +1
We study the magnetic field-dependence of the thermal conductivity due to magnetic excitations in frustrated spin-1/2 Heisenberg chains. Near the saturation field, the system is de…
Principal Chiral Model in Correlated Electron Systems
Cristian D. Batista, Mikhail Shifman, Zhentao Wang +1
We discuss noncollinear magnetic phenomena whose local order parameter is characterized by more than one spin vector. By focusing on the simple cases of 2D triangular and 3D pyroch…
Dynamical structure factor of the triangular antiferromagnet: the Schwinger boson theory beyond the mean field approach
E. A. Ghioldi, M. G. Gonzalez, Shang-Shun Zhang +4
We compute the zero temperature dynamical structure factor of the triangular lattice Heisenberg model (TLHM) using a Schwinger boson approach that includes the Gauss…
Spin-orbit interaction driven dimerization in one dimensional frustrated magnets
Shang-Shun Zhang, Nitin Kaushal, Elbio Dagotto +1
We study the effect of spin-orbit interaction on one-dimensional U(1)-invariant frustrated magnets with dominant critical nematic fluctuations. The spin-orbit coupling explicitly b…