arXiv subjects

Dong-Hao Guan

Publications and source records attributed to Dong-Hao Guan.

4 recordsLinked to original sources

arXiv2026

Decomposing Fractional Quantum Hall Wave Functions via Operator Contraction Multiplication

We develop a general algebraic scheme to decompose fractional quantum Hall (FQH) wave functions based on the operator contraction multiplication. By introducing fermionic and bosonic operators and establishing three fundamental contraction rules, we achieve an exact decomposition of Laughlin states. This approach naturally extends to multi-component systems by factorizing coupled Jastrow factors via resultants and elementary symmetric polynomials, enabling the first complete decomposition of Halperin states. For Halperin ($2,2,1$) state, we explicitly derive its basic expansion, identify root configurations, and reveal intra- and inter-color squeezing operators, thereby uncovering the underlying generalized Pauli principle. Using this method, we compute orbital entanglement spectra for up to $16$ particles with decomposition dimensions exceeding $10^{11}$, obtaining edge excitation sequences that precisely match chiral Luttinger liquid theory. Our framework breaks through the longstanding limitations of Jack polynomials, provides a unified decomposition for both single- and multi-component FQH states, and opens a new avenue for exploring wave functions for more complex FQH states.

cond-mat.str-el↗

arXiv2026

Alternative $ν+ν$-picture of bosonic fractional Chern insulators at high filling factors in multiple flat-band systems

Most fractional quantum Hall states have been traditionally identified within a single energy band, such as the lowest Landau level or topological flat band. As more particles are introduced, they inevitably populate higher energy bands. Whether the inclusion of multiple topological bands leads to new physics remains an open question. Here, we propose a universal picture applicable at higher filling factors $ν\geq 1$ in bosonic systems: the occupied bands tend to coalesce into an effective single topological band characterized by a total Chern number $\vert C\vert$, the sum of the Chern number of all occupied lower topological flat bands. Using a Kekulé lattice model with two lower flat bands featuring a total Chern number $C=1$, regardless of their specific configurations, we identify the emergence of a $\frac{1}{2}$ fractional Chern insulator (FCI) state at integer filling factor $ν=1$, followed by the Jain sequence states $\frac{2}{3}$ and $\frac{3}{4}$ at filling $ν=\frac{4}{3}$ and $\frac{6}{4}$. That is a $ν+ν$ picture, rather than the generally expected $1+ν^{\prime}$ picture, where $ν^{\prime}$ is the permitted FCI filling factor in the single second topological flat band. Our findings deepen the understanding of FCI states and open avenues for discovering exotic fractional topological phases in multiband systems.

cond-mat.str-el↗

arXiv2025

Square lattice model with staggered magnetic fluxes: zero Chern number topological states and topological flat bands

Staggered magnetic fluxes (SMF) play a crucial role in achieving Chern insulators (CIs), by which a series of CI models have been established on various lattices. In addition, SMF induced higher-order topological insulator (HOTI) in a lattice model has been reported. In this work, we propose a square lattice model with SMF. We find intracellular SMF can induce zero-Chern-number topological insulator (ZCNTI) at quarter filling which hosts topologically protected edge states characterized by the quantized polarization, in analogy to the topological state in two dimensional Su-Schrieffer-Hegger model. When lattice dimerization and intracellular SMF are introduced, there exists HOTI state at half filling. Furthermore, this model hosts topological flat band (TFB) by considering the next-nearest-neighbor hoppings. Several fractional Chern insulator states are investigated when hard-core bosons are filled into this TFB model.

cond-mat.str-el↗

arXiv2024

Topological flat bands in hyperbolic lattices

Topological flat bands (TFBs) provide a promising platform to investigate intriguing fractionalization phenomena, such as the fractional Chern insulators (FCIs). Most of TFB models are established in two-dimensional Euclidean lattices with zero curvature. In this work, we systematically explore TFBs in a class of two-dimensional non-Euclidean lattices with constant negative curvature, {\emph i.e.,} the hyperbolic analogs of the kagome lattice. Based on the Abelian hyperbolic band theory, TFBs have been respectively found in the heptagon-kagome, the octagon-kagome, the nonagon-kagome and the decagon-kagome lattices by introducing staggered magnetic fluxes and the next nearest-neighbor hoppings. The flatness ratios of all hyperbolic TFB models are more than 15, which suggests that the hyperbolic FCIs can be realized in these TFB models. We further demonstrate the existence of a $ν=1/2$ FCI state with open boundary conditions when hard-core bosons fill into these hyperbolic TFB models.

cond-mat.str-el↗