High-energy spin waves in the spin-1 square-lattice antiferromagnet La2NiO4

Physical Review Research American Physical Society 5:3 (2023) 033113

Authors:

An Petsch, Ns Headings, D Prabhakaran, Ai Kolesnikov, Cd Frost, At Boothroyd, R Coldea, Sm Hayden

Abstract:

Inelastic neutron scattering is used to study the magnetic excitations of the S=1 square-lattice antiferromagnet La2NiO4. We find that the spin waves cannot be described by a simple classical (harmonic) Heisenberg model with only nearest-neighbor interactions. The spin-wave dispersion measured along the antiferromagnetic Brillouin-zone boundary shows a minimum energy at the (1/2,0) position as is observed in some S=1/2 square-lattice antiferromagnets. Thus, our results suggest that the quantum dispersion renormalization effects or longer-range exchange interactions observed in cuprates and other S =1/2 square-lattice antiferromagnets are also present in La2NiO4. We also find that the overall intensity of the spin-wave excitations is suppressed relative to linear spin-wave theory, indicating that covalency is important. Two-magnon scattering is also observed.

Tuning the confinement potential between spinons in the Ising chain CoNb2O6 using longitudinal fields and quantitative determination of the microscopic Hamiltonian

(2023)

Authors:

Leonie Woodland, David Macdougal, Ivelisse Cabrera, Jordan D Thompson, D Prabhakaran, Robert I Bewley, Radu Coldea

Erratum: Quantifying and Controlling Entanglement in the Quantum Magnet Cs_{2}CoCl_{4} [Phys. Rev. Lett. 127, 037201 (2021)].

Physical review letters 130:12 (2023) 129902

Authors:

Pontus Laurell, Allen Scheie, Chiron J Mukherjee, Michael M Koza, Mechtild Enderle, Zbigniew Tylczynski, Satoshi Okamoto, Radu Coldea, D Alan Tennant, Gonzalo Alvarez

Abstract:

This corrects the article DOI: 10.1103/PhysRevLett.127.037201.

Excitations of quantum Ising chain CoNb2O6 in low transverse field: quantitative description of bound states stabilized by off-diagonal exchange and applied field: data archive

University of Oxford (2023)

Authors:

Leonie Woodland, Izabella Lovas, Mark Telling, Dharmalingam Prabhakaran, Leon Balents, Radu Coldea

Abstract:

The deposited package contains experimental single crystal inelastic neutron scattering data probing the spin dynamics in the quantum Ising chain magnet CoNb2O6 in applied transverse magnetic field together with corresponding theoretical calculations of the spin dynamics. A matlab script to read and plot all data in ASCII files is also supplied.

Negative-chirality order in S = 1/2 kagome antiferromagnet CdCu3(OH)6(NO3)2·H2O

Physical Review B American Physical Society 106:2 (2022) 24401

Authors:

Yoshihiko Ihara, Ryoga Hiyoshi, Masakazu Shimohashi, Kaoru Hayashi, Ryutaro Okuma, Fabio Orlandi, Pascal Manuel, Gøran J Nilsen, Zenji Hiroi

Abstract:

Neutron diffraction and nuclear magnetic resonance (NMR) measurements have been used to analyze the magnetic structure in the S = 1 2 kagome antiferromagnet CdCu 3 ( OH ) 6 ( NO 3 ) 2 ⋅ H 2 O . Below the magnetic ordering temperature T N ≃ 4 K , magnetic Bragg reflections at (101) and (100) were found in the neutron diffraction pattern, which suggests a q = 0 magnetic structure. Furthermore, the vector spin chirality for the q = 0 structure was successfully identified from the internal field direction obtained by the 14 N -NMR measurement, previous magnetization measurements, and magnetic symmetry analysis. Our findings point to a chirality-ordered magnetic structure with negative vector chirality and ⟨ 100 ⟩ anisotropy.