Homotopy, symmetry, and non-Hermitian band topology

K Yang, Z Li, JLK König, L Rødland… - Reports on Progress …, 2024 - iopscience.iop.org
Non-Hermitian matrices are ubiquitous in the description of nature ranging from classical
dissipative systems, including optical, electrical, and mechanical metamaterials, to scattering …

Enhanced eigenvector sensitivity and algebraic classification of sublattice-symmetric exceptional points

K Yang, I Mandal - Physical Review B, 2023 - APS
Exceptional points (EPs) are degeneracy of non-Hermitian Hamiltonians, at which the
eigenvalues, along with their eigenvectors, coalesce. Their orders are given by the Jordan …

Majorana quasiparticles emergent in Kitaev spin liquid

J Nasu - Progress of Theoretical and Experimental Physics, 2024 - academic.oup.com
This paper reviews the nature of two quasiparticles, the Majorana fermion and vison,
emergent in the Kitaev model, mainly from the theoretical point of view. We demonstrate how …

Magnetic field effects on the Kitaev model coupled to environment

K Fukui, Y Kato, Y Motome - Physical Review B, 2024 - APS
Open quantum systems display unusual phenomena not seen in closed systems, such as
new topological phases and unconventional phase transitions. An interesting example was …

Spectral evidence for Dirac spinons in a kagome lattice antiferromagnet

Z Zeng, C Zhou, H Zhou, L Han, R Chi, K Li, M Kofu… - Nature Physics, 2024 - nature.com
Emergent quasiparticles with a Dirac dispersion in condensed matter systems can be
described by the Dirac equation for relativistic electrons, in analogy with Dirac particles in …

Non-Hermitian generalizations of the Yao-Lee model augmented by SO (3)-symmetry-breaking terms

I Mandal - arxiv preprint arxiv:2401.08568, 2024 - arxiv.org
We investigate non-Hermitian versions of the Yao-Lee model supplemented by various
kinds of SO (3)-symmetry-breaking terms, preserving the solvability of the model. The parent …

Dirac quantum spin liquid emerging in a kagome-lattice antiferromagnet

Z Zeng, C Zhou, H Zhou, L Han, R Chi, K Li… - arxiv preprint arxiv …, 2023 - arxiv.org
Emerging quasi-particles with Dirac dispersion in condensed matter physics are analogous
to their cousins in high-energy physics in that both of them can be described by the Dirac …

Disorder and non-Hermiticity in Kitaev spin liquids with a Majorana Fermi surface

L Rødland, C Ortega-Taberner, M Agarwal… - Physical Review B, 2024 - APS
We study the effect of disorder on Z 2 quantum spin liquids with a Majorana Fermi line
(respectively a surface in three dimensions), and we show that depending on the …

Entanglement transitions in a periodically driven non-Hermitian Ising chain

T Banerjee, K Sengupta - Physical Review B, 2024 - APS
We study entanglement transitions in a periodically driven Ising chain in the presence of an
imaginary transverse field γ as a function of drive frequency ω D. In the high drive amplitude …

Role of quantum geometric tensor on wavepacket dynamics in two-dimensional non-Hermitian systems

YMR Hu, EA Ostrovskaya, E Estrecho - arxiv preprint arxiv:2412.08141, 2024 - arxiv.org
The quantum geometric tensor (QGT) characterizes the local geometry of quantum states,
and its components directly account for the dynamical effects observed, eg, in condensed …