arXiv subjects

Minghuan Zeng

Publications and source records attributed to Minghuan Zeng.

14 recordsLinked to original sources

arXiv2026

The odd-parity altermagnetism induced reconstruction of the Chern-insulating phase in Haldane-Hubbard model

Odd-parity altermagnetism(ALM) extends compensated collinear magnetism beyond the even-parity spin splitting of conventional altermagnets, but its role in correlated topological phases remains largely unexplored. Using the cluster slave-spin method, we show that the odd-parity ALM appearing in the ALM Chern-insulating phase of Haldane-Hubbard model significantly reconstructs the local topology in the conventional Chern-insulating phase, while the total Chern number remains unchanged compared to the Chern-insulating phase. The Berry curvature becomes spin and valley selective; zigzag ribbons develop chiral-symmetry-breaking edge states; while armchair ribbons remain inversion symmetric. The optical response mirrors this separation between the local reconstruction and the global topology: low-energy spectra are governed by quasiparticles near the gap, whereas the low-frequency Hall conductivity stays quantized, $σ_{\rm T\uparrow}(Ω\to 0)=σ_{\rm T\downarrow}(Ω\to 0)=e^2/h$. These results establish the Haldane-Hubbard model as a minimal correlated platform for odd-parity altermagnetic topology.

cond-mat.str-el↗

arXiv2026

Impurity-Scattering Assisted Umklapp Scattering as the Origin of Low-Temperature Resistivity in the Normal-State of Cuprate Superconductors

The transport experiments reveal that the low-temperature resistivity in the normal-state of cuprate superconductors is quadratic in temperature (T-quadratic) in the underdoped pseudogap phase, while it is linear in temperature (T-linear) in the overdoped strange-metal phase, however, the full understanding of these different behaviours is still a challenging issue. Here starting from the microscopic electronic structure of cuprate superconductors, the low-temperature resistivity in the normal-state is investigated from the underdoped pseudogap phase to the overdoped strange-metal phase. It is shown that the mechanism requires both the impurity scattering and the umklapp scattering: the impurity scattering is needed to restrict the modification of the distribution function to at around the antinodal region,while the impurity-scattering assisted umklapp scattering from a spin excitation is at the heart of the behaviour in the low-temperature resistivity, where the doping dependence of the temperature scale exists, and presents a similar behavior of the antinodal spin pseudogap crossover temperature. In the low-temperature region above the temperature scale in the overdoped strange-metal phase, the resistivity is T-linear, however, in the low-temperature region below the temperature scale in the underdoped pseudogap phase, the opening of the spin pseudogap lowers the spin excitation density of states at around the antinodal region, which reduces the strength of the electron umklapp scattering from a spin excitation associated with the antinode, and thus leads to a T-quadratic behaviour of the resistivity.

cond-mat.supr-con↗

arXiv2026

The odd-parity altermagnetism: A spin group study

Following recent intensive studies on altermagnetism(ALM) characterized by non-relativistic even-parity spin splitting, realizing unconventional odd-parity magnetism has also attracted increasing interest. Here, using symmetry arguments based on spin-group analyses, we elucidate sufficient conditions for the emergence of odd-parity spin splitting in collinear antiferromagnetic systems, which is further established as the standard odd-parity ALM. It is derived that the odd-parity ALM arises from the following criteria: (i)the breaking nonmagnetic time reversal symmetry(TRS), i.e., the breaking real-space TRS; (ii)the long-range collinear compensated magnetism; (iii)the symmetry $[C_{2}||\bar{E}]$ or $[C_{2}||M]$ connecting opposite-spin sublattices, where $C_{2}$, $\bar{E}$, and $M$ respectively represent a $180^{\circ}$ rotation around the axis perpendicular to spins, the inversion, and the mirror reflection separating opposite-spin sublattices, directly reflecting the high-order harmonic($l\ge3$) and the $p$-wave($l=1$) odd-parity ALM, respectively. Moreover, we utilize the well-known Haldane-Hubbard model to identify odd-parity spin splitting in the collinear ALM ground state, where (i)the nonmagnetic TRS is broken by opposite sublattice currents coming from the Haldane hopping; (ii)the symmetry $[C_{2}||\bar{E}]$ is ensured because the currents flowing on opposite-spin sublattices are reversed.

cond-mat.str-el↗

arXiv2026

Oriented Triplet $p$-Wave Pairing from Fermi surface Anisotropy and Nonlocal Attraction

Using constrained-path quantum Monte Carlo, we map the ground-state phase diagram versus the nearest-neighbor (NN) attraction $V$ and spin-dependent hopping anisotropy $α$ for the two-dimensional attractive $t$--$U$--$V$ Hubbard model at filling $n\simeq0.85$. We identify an onsite $s$-wave superfluid, a Cooper pair Bose metal with an uncondensed Bose surface, and an oriented equal-spin triplet $p$-wave pairing phase. The NN attraction activates the odd-parity channel, while hopping anisotropy suppresses the competing $s$-wave coherence and selects a $p_x/p_y$ polar axis, and thus lowers the critical $|V_c|$ for the onset of triplet-dominant $p$-wave pairing. A channel-resolved Landau analysis provides a criterion for the Landau $p$-wave scale $V_c^{\mathrm L}(α)$, consistent with the observed anisotropy dependence of $|V_c|$. Our results establish how NN interaction and Fermi surface anisotropy cooperate to generate the oriented triplet $p$-wave pairing, and suggest that cold-atom and altermagnetic platforms could potentially realize this mechanism.

cond-mat.supr-con↗

arXiv2025

Unusual electronic ordering in the pseudogap phase of underdoped cuprate superconductors

The pseudogap phase of the underdoped cuprate superconductors harbours diverse manifestations of different ordered electronic-states, and then these ordered electronic-states coexist or compete with superconductivity. Here starting from the microscopic electron propagator, the nature of the ordered electronic-states in the pseudogap phase is investigated within the $T$-matrix approach. This $T$-matrix is derived in terms of the inverse of matrix for various kinds of a single impurity, and then is used to evaluate the local density of states (LDOS) by the involvement of all the quasiparticle excitations and scattering processes. It is shown that a number of the anomalous properties in the underdoped cuprate superconductors is directly correlated to the opening of the normal-state pseudogap: (i) the structure of the microscopic octet scattering model generated by the normal-state pseudogap is essentially the same both in the superconducting (SC)-state and pseudogap phase, which naturally leads to that the quasiparticle scattering interference octet phenomenology observed in the SC-state exists in the pseudogap phase; (ii) however, the spectral weight at around the antinodal region in the SC-state is gapped out completely by both the SC gap and normal-state pseudogap, while it in the pseudogap phase is suppressed partially by the normal-state pseudogap, this directly leads to that the non-dispersive checkerboard charge ordering with a finite wave vector ${\bf Q}$ appears in the pseudogap phase only. The theory therefore also shows that the electronic-states affected by the normal-state pseudogap exhibit the LDOS modulation spectrum organization.

cond-mat.supr-con↗

arXiv2025

The spin Hall conductivity in the hole-doped bilayer Haldane-Hubbard model with odd-parity ALM

Spin current generated electrically is among the core phenomena of spintronics for driving high-performance spin device applications. Here, on the basis of systematic investigations for the hole doped single-layer Haldane-Hubbard(HH) model, we propose a new bilayer HH model to realize the compensated odd-parity spin splitting and the $T$-even spin Hall conductivity where the two layers are connected by the time reversal transformation. Our results show that the vanishing layer-dependent electric potential $V_{L}$ gives rise to odd-parity ALM protected by the combined symmetry $TM_{xy}$ with $T$ and $M_{xy}$ being the time reversal and mirror reflection perpendicular to $z$ axis, and the $T$-even spin Hall conductivity simultaneously. In addition, though the staggered magnetization within each layer is substantially impacted by the layer-dependent electric potential, small $V_{L}$'s only bring negligible changes to the net magnetization and the spin Hall conductivity, indicating that the alternating spin splitting in momentum space and the spin Hall conductivity are insusceptible to external elements. Most importantly, our work provides a general framework for the simultaneous realization of the compensated odd-parity spin splitting in momentum space and the spin Hall conductivity in collinear magnets, in terms of stacked multi-layer systems.

cond-mat.str-el↗

arXiv2025

Unusual electronic structure in underdoped cuprate superconductors

The underdoped cuprate superconductors are characterized by the opening of the pseudogap, while such an aspect of the pseudogap effect should be reflected in the low-energy electronic structure (LEES). Here the effect of the pseudogap on LEES in the underdoped cuprate superconductors is investigated within the kinetic-energy-driven superconductivity. The strong coupling of the electrons with the spin excitation induces the pseudogap-state in the particle-hole channel and superconducting (SC) state in the particle-particle channel, where the pseudogap and SC gap respectively originate from the electron normal and anomalous self-energies, and are evaluated by taking into account the vertex correction. As a natural consequence of the interplay between the pseudogap-state and SC-state, the SC transition temperature Tc exhibits a dome-like shape of the doping dependence, however, in a striking contrast to Tc in the underdoped regime, the pseudogap crossover temperature T* is much higher than Tc in the underdoped regime, and then it decreases with the increase of doping, eventually disappearing together with Tc at the end of the SC dome. Concomitantly, the spectral weight on the electron Fermi surface (EFS) at around the antinodal region is suppressed strongly by this pseudogap, and then EFS is truncated to form four disconnected Fermi arcs centered around the nodal region with the largest spectral weight located at around the tips of the disconnected Fermi arcs. Moreover, the dip in the peak-dip-hump structure observed in the energy distribution curve and checkerboard charge ordering found in the ARPES autocorrelation are intrinsically connected with the emergence of the pseudogap. The theory therefore indicates that the same spin excitation that governs both the pseudogap-state and SC-state naturally leads to the exotic features of LEES in the underdoped cuprate superconductors.

cond-mat.supr-con↗

arXiv2025

Spontaneously broken chiral symmetry in the interacting Kane-Mele model

The essential properties of the half-filled interacting Kane-Mele model on a hexagon lattice is studied using the slave rotor approach. It is shown clearly that a long-range charge-order state with spontaneously broken chiral symmetry emerges in the weak and moderate interaction regimes, as well as a presumed site-selected topological Mott insulator state in the stronger interaction regime with U < UMott, where UMott is the critical interaction strength, and in the case of U > UMott, the system is transited into the usual topological Mott state. This new charge-order state has lower energy compared to the usual topological band insulator (TBI) state with chiral symmetry, and thus is named as non-chiral TBI state. More specifically, in this non-chiral TBI state without any long-range magnetic order, a long-range charge order with different electron occupation on two sublattices appears in the absence of external sublattice field. The spontaneously broken chiral symmetry gives rise to a special helical edge state, which has different spin accumulation on opposite edges of the cylinder with periodic boundary condition in the zigzag direction, and thus leads to a net spin current across the system. This net spin current would be further strengthened if the nearest neighbor electron Coulomb interaction is taken into account as well, because it is favorable for the long-range charge order with different electron occupation on sublattices.

cond-mat.str-el↗

arXiv2025

Correlation between the strength of low-temperature T-linear normal-state resistivity and $T_{\rm c}$ in overdoped electron-doped cuprate superconductors

The recently observed an intimate link between the nature of the strange metallic normal-state and superconductivity in the overdoped electron-doped cuprate superconductors is calling for an explanation. Here the intrinsic correlation between the strength of the low-temperature linear-in-temperature normal-state resistivity and superconducting transition temperature $T_{\rm c}$ in the overdoped electron-doped cuprate superconductors is studied within the framework of the kinetic-energy-driven superconductivity. On the one hand, the main ingredient is identified into a electron pairing mechanism involving the spin excitation, and then $T_{\rm c}$ has a dome-like shape doping dependence with the maximal $T_{\rm c}$ that occurs at around the optimal electron doping. On the other hand, in the normal-state above $T_{\rm c}$, the low-temperature linear-in-temperature normal-state resistivity in the overdoped regime arises from the momentum relaxation due to the electron umklapp scattering mediated by the same spin excitation. This same spin excitation that governs both the electron umklapp scattering responsible for the low-temperature linear-in-temperature normal-state resistivity and electron pairing responsible for superconductivity naturally generates a correlation between the strength of the low-temperature linear-in-temperature normal-state resistivity and $T_{\rm c}$ in the overdoped regime.

cond-mat.supr-con↗

arXiv2024

Quasiparticle scattering interference in cuprate superconductors

The quasiparticle scattering interference (QSI) is intimately related to the nature of the quasiparticle and of its interplay with a variety of electronic orders and superconductivity. Here starting from the microscopic octet scattering model, the nature of QSI in cuprate superconductors is studied in the $T$-matrix approach. In particular, a new method of the inversion of matrix is developed to accurately derive the $T$-matrix for various kinds of impurities, and then the obtained $T$-matrix is employed to calculate the local density of states (LDOS). It is shown that the overall features of the LDOS modulation can be described qualitatively by taking into account the quasiparticle scattering from a single impurity on the kinetic-energy-driven homogeneous superconducting-state, where the QSI scattering wave vectors ${\bf q}_{i}$ and the related QSI peak dispersions are internally consistent within the octet scattering model. However, the pronounced QSI peaks in the momentum-space LDOS modulation pattern for a single impurity are smeared heavily in the case for multiple impurities, and then the momentum-space LDOS modulation for multiple impurities exhibits a speckle pattern. Moreover, the momentum-space LDOS modulation for Gaussian-random-distribution of on-site impurity at a relatively large deviation displays a similar behavior of the LDOS modulation for multiple impurities. The theory also indicates that the impurity weight linearly increases with the increase of the impurity-scattering strength for the weak scattering strength and tends to saturate in the strong scattering strength, while it decreases with the increase of the impurity-scattering screening length for the short screening-length and saturates in the long screening-length.

cond-mat.supr-con↗

arXiv2024

Low-temperature T$^{2}$ resistivity in the underdoped pseudogap phase versus T-linear resistivity in the overdoped strange-metal phase of cuprate superconductors

The transport experiments demonstrate a dramatic switch from the low-temperature linear in temperature (T-linear) resistivity in the overdoped strange-metal phase of cuprate superconductors to the low-temperature quadratic in temperature (T-quadratic) resistivity in the underdoped pseudogap phase, however, a consensus on the origin of this unusual switch is still lacking. Here the resistivity in the underdoped pseudogap phase of cuprate superconductors is investigated using the Boltzmann transport equation. The resistivity originates from the electron umklapp scattering mediated by the spin excitation, however, the dominant contribution mainly comes from the antinodal umklapp scattering. In particular, a low temperature $T_{\rm scale}$ scales with $Δ^{2}_{p}$ in the underdoped regime due to the opening of a momentum dependent spin pseudogap, where $Δ_{p}$ is the minimal umklapp vector at the antinode. Moreover, this $T_{\rm scale}$ decreases with the increase of doping in the underdoped regime, and then is reduced to a very low temperature in the overdoped regime. In the underdoped regime, the resistivity is T-quadratic at the low temperatures below $T_{\rm scale}$, where the strength of the T-quadratic resistivity weakens as the doping is raised. However, in the overdoped regime, the resistivity is T-linear at the low temperatures above $T_{\rm scale}$. The results in this paper together with the recent study on the resistivity in the overdoped regime therefore show that the electron umklapp scattering from a spin excitation responsible for the low-temperature T-linear resistivity in the overdoped regime naturally produces the low-temperature T-quadratic resistivity in the underdoped regime resulting from the opening of a momentum dependent spin pseudogap.

cond-mat.supr-con↗

arXiv2023

Low-temperature T-linear resistivity in the strange metal phase of overdoped cuprate superconductors due to umklapp scattering from a spin excitation

The strange-metal phase of overdoped cuprate superconductors exhibits a linear in temperature resistivity in the low temperature, however, the origin of this remarkable anomaly is still not well understood. Here the linear temperature dependence of the resistivity in the strange-metal phase of overdoped cuprate superconductors is investigated. The momentum dependence of the transport scattering rate arising from the umklapp scattering between electrons by the exchange of the spin excitations is derived and employed to calculate the resistivity by making use of the Boltzmann equation. It is shown that the resistivity is mainly dominated by the antinodal and nodal umklapp scattering. In particular, a very low temperature $T_{\rm scale}$ scales with $Δ^{2}_{p}$, where $Δ_{p}$ is the minimum umklapp vector at the antinode. In the low temperature above $T_{\rm scale}$, the resistivity is linear in temperature with the temperature linear coefficient that decreases with the increase of doping, however, in the far lower temperature below $T_{\rm scale}$, the resistivity is instead quadratic in temperature. The theory also shows that the same spin excitation that acts like a bosonic glue to hold the electron pairs together also mediates scattering of electrons in the strange-metal phase responsible for the linear in temperature resistivity in the low temperature.

cond-mat.supr-con↗

arXiv2023

Microwave conductivity due to impurity scattering in cuprate superconductors

The microwave surface impedance measurements on cuprate superconductors provide the crucial information of the effect of the impurity scattering on the quasiparticle transport, however, the full understanding of the effect of the impurity scattering on the quasiparticle transport is still a challenging issue. Here based on the microscopic octet scattering model, the effect of the impurity scattering on the low-temperature microwave conductivity in cuprate superconductors is investigated in the self-consistent $T$-matrix approach. The impurity-dressed electron propagator obtained in the Fermi-arc-tip approximation of the quasiparticle excitations and scattering processes is employed to derive the electron current-current correlation function by taking into account the impurity-induced vertex correction. It is shown that the microwave conductivity spectrum is a non-Drude-like, with a sharp cusp-like peak extending to zero-energy and a high-energy tail falling slowly with energy. Moreover, the microwave conductivity decreases with the increase of the impurity concentration or with the increase of the strength of the impurity scattering potential. In a striking contrast to the dome-like shape of the doping dependence of the superconducting transition temperature, the microwave conductivity exhibits a reverse dome-like shape of the doping dependence. The theory also show that the highly unconventional features of the microwave conductivity are generated by both the strong electron correlation and impurity-scattering effects.

cond-mat.supr-con↗

arXiv2022

Influence of impurities on electronic structure in cuprate superconductors

The impurity is inherently manifest in cuprate superconductors, as cation substitution or intercalation is necessary for the introduction of charge carriers, and its influence on the electronic state is at the heart of a great debate in physics. Here based on the microscopic octet scattering model, the influence of the impurity scattering on the electronic structure of cuprate superconductors is investigated in terms of the self-consistent T-matrix approach. The impurity scattering self-energy is evaluated firstly in the Fermi-arc-tip approximation of the quasiparticle excitations and scattering processes, and the obtained results show that the decisive role played by the impurity scattering self-energy in the particle-hole channel is the further renormalization of the quasiparticle band structure with a reduced quasiparticle lifetime, while the impurity scattering self-energy in the particle-particle channel induces a strong deviation from the d-wave behaviour of the superconducting gap, leading to the existence of a finite gap over the entire electron Fermi surface. Moreover, these impurity scattering self-energies are employed to study the exotic features of the line-shape in the quasiparticle excitation spectrum and the autocorrelation of the quasiparticle excitation spectra, and the obtained results are then compared with the corresponding experimental data. The theory therefore also indicates that the unconventional features of the electronic structure in cuprate superconductors is generated by both the strong electron correlation and impurity scattering.

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