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Guo-Hua Sun

Publications and source records attributed to Guo-Hua Sun.

At least 19 recordsLinked to original sources
arXiv2026

New mechanism for fermion localization in $f(T,T_G)$-brane

We investigate the localization of fermionic fields in a five-dimensional braneworld scenario within the framework of modified teleparallel gravity described by a general $f(T,T_G)$ function. Considering a non-minimal coupling between a Dirac spinor and the torsional invariants, we derive the effective Schrödinger-like equations governing the Kaluza-Klein modes. We showed that the contribution of the teleparallel Gauss-Bonnet term significantly modifies the effective potentials and, consequently, the localization properties. The zero-mode analysis reveals that only one chiral component can be localized on the brane, with the degree of confinement depending on the chosen model. In the massive sector, the spectrum is continuous, but resonant states arise due to the internal structure of the potentials. Additionally, we employ information-theoretic measures, such as Shannon entropy and relative probability, to quantify the localization mechanism. Our results show that the torsional modifications induce a nontrivial redistribution of information, exhibiting stronger localization. These findings highlight the role of higher-order torsional terms in shaping fermionic localization and resonance structures in braneworld scenarios.

hep-th↗
arXiv2026

RFOX (Rotated-Field Oscillatory eXchange) quantum algorithm: Towards Parameter-Free Quantum Optimizers

We introduce RFOX (Rotated-Field Oscillatory eXchange), a parameter-free quantum algorithm for combinatorial optimization that combines an almost constant non-stoquastic $XX$ catalyst with a weak harmonic $ZX$ counter-diabatic term. Using the Floquet-Magnus expansion, we derive an effective Hamiltonian whose leading-order $\mathcal{O}(δ/ω)$ corrections yield local $Y$ fields, field-modulated 2-body terms, and poly-local 3-body topological interactions driven by graph connectivity. This structure ensures a nearly flat instantaneous spectral gap, preventing the unpredictable gap collapses typical of conventional $X$ (stoquastic), $XX$, and $X+sXX$ (non-stoquastic) driver schedules. Extensive noiseless simulations and physical hardware experiments on IBM Quantum processors (up to 20 qubits) validate our spectral predictions. RFOX consistently attains near-optimal or exact ground states in the random-field Ising model using up to an order of magnitude fewer Trotter slices, with an advantage that grows alongside problem disorder. These results suggest that fixed-gap, non-stoquastic drivers augmented with analytically derived counter-diabatic terms offer a scalable, tuning-free route for quantum optimization.

quant-ph↗
arXiv2026

Exploring Entanglement and Parameter Sensitivity in QAOA through Quantum Fisher Information

Quantum Fisher Information (QFI) can be used to quantify how sensitive a quantum state reacts to changes in its variational parameters, making it a natural diagnostic for algorithms such as the Quantum Approximate Optimization Algorithm (QAOA). We perform a systematic QFI analysis of QAOA for Max-Cut on cyclic and complete graphs with $N = 4 - 10$ qubits. Two mixer families are studied, RX-only and hybrid RX-RY, with depths $p = 2, 4, 6$ and $p = 3, 6, 9$, respectively, and with up to three entanglement stages implemented through cyclic- or complete-entangling patterns. Complete graphs consistently yield larger QFI eigenvalues than cyclic graphs; none of the settings reaches the Heisenberg limit ($4N^2$), but several exceed the linear bound ($4N$). Introducing entanglement primarily redistributes QFI from diagonal to off-diagonal entries: non-entangled circuits maximize per-parameter (diagonal) sensitivity, whereas entangling layers increase the covariance fraction and thus cross-parameter correlations, with diminishing returns beyond the first stage. Leveraging these observations, we propose, as a proof of concept, a QFI-Informed Mutation (QIm) heuristic that sets mutation probabilities and step sizes from the normalized diagonal QFI. On 7- and 10-qubit instances, QIm attains higher mean energies and lower variance than equal-probability and random-restart baselines over 100 runs, underscoring QFI as a lightweight, problem-aware preconditioner for QAOA and other variational quantum algorithms.

quant-ph↗
arXiv2026

Phase Transitions, Geodesic Structure, and Thermodynamic Properties Measurement of Einstein-Maxwell-Power Yang-Mills Black Hole Models

In this work, we test the geometrical structure and thermodynamic properties of the Einstein-Maxwell-Power-Yang-Mills black hole (BH) models, which constitute a nonlinear generalization of the standard Einstein-Yang-Mills theory through the inclusion of a power-law Yang-Mills invariant. Also, we begin by analyzing the spacetime geometry via the metric function $f(r)$ and examine the modifications induced by the electromagnetic charge and nonlinear Yang-Mills parameter on the horizon structure, causal structure, and gravitational potential. Subsequently, the dynamics of photons and massive particles are explored through the study of null and timelike geodesics, allowing the determination of the effective potential, photon sphere radius, and associated BH shadow. Also, the stability of circular photon orbits is quantified using the Lyapunov exponent, which characterizes the timescale of orbital instability and provides a direct link to observable photon ring features. For massive particles, the innermost stable circular orbit (ISCO) is calculated, illustrating the influence of BH parameters on the dynamics of accretion disks. From the thermodynamic viewpoint, we compute the principal thermodynamic quantities, including the BH mass, Hawking temperature, Bekenstein-Hawking entropy, heat capacity, and Gibbs free energy, to assess both local and global stability of the system. The divergence of the heat capacity signals the occurrence of second-order phase transitions, whereas the Gibbs free energy analysis identifies possible first-order phase transitions between distinct thermodynamic configurations. In this context, our results demonstrate that the nonlinear Yang-Mills parameter strongly affects the spacetime geometry, particle dynamics, and thermodynamic phase structure, shifting the location of stability regions and critical points associated with phase transitions.

gr-qc↗
arXiv2025

Thermal Behavior of Generalized Black-Bounce Black Hole Model

In this work, we tested the thermal behavior of a class of regular black hole solutions defined as generalized black-bounce spacetimes. We introduce several novel configurations governed by different mass functions and geometric deformations, illustrated by parameters controlling regularity and horizon structure. Using the Hamilton Jacobi tunneling method, we compute the Hawking temperature associated with each model and analyze its dependence on the underlying parameters. We find that all proposed geometries are free of curvature singularities and exhibit positive, well defined quasi-local masses in the Hernandez Misner Sharp formalism. Also, we demonstrate that these models may possess multiple horizons, including extremal and asymmetric cases, while typically violating classical energy conditions in the vicinity of the bounce. Our results show and illustrate the structure and thermodynamic stability of these regular solutions.

gr-qc↗
arXiv2025

Thermodynamics of BTZ-type charged black holes in Bopp Podolsky electrodynamics

We tested the thermodynamic properties of charged BTZ-type black holes (BHs) in the framework of Bopp Podolsky electrodynamics, a higher derivative extension of Maxwells theory that preserves gauge invariance while introducing a massive photon mode. Using a perturbative approach, we derive first and second order corrections to the metric and electric field, revealing how the Bopp Podolsky parameter b modifies the geometry and horizon structure. Unlike in four dimensional illustrations, where such corrections can lead to wormhole solutions, the (2+1)dimensional case retains a black hole interpretation, albeit with curvature dependent deformations that vanish asymptotically. We compute the Hawking temperature via the Hamilton Jacobi tunneling method, demonstrating its dependence on both the cosmological constant and the Bopp Podolsky coupling. Our results indicate that while energy conditions are marginally violated for certain parameter regimes, the BHs thermodynamic behavior remains well-defined, with temperature corrections emerging from the interplay between higher derivative electrodynamics and the lower dimensional gravitational background.

gr-qc↗
arXiv2025

Parameter optimization comparison in QAOA using Stochastic Hill Climbing with Random Re-starts and Local Search with entangled and non-entangled mixing operators

This study investigates the efficacy of Stochastic Hill Climbing with Random Restarts (SHC-RR) compared to Local Search (LS) strategies within the Quantum Approximate Optimization Algorithm (QAOA) framework across various problem models. Employing uniform parameter settings, including the number of restarts and SHC steps, we analyze LS with two distinct perturbation operations: multiplication and summation. Our comparative analysis encompasses multiple versions of max-cut and random Ising model (RI) problems, utilizing QAOA models with depths ranging from $1L$ to $3L$. These models incorporate diverse mixing operator configurations, which integrate $RX$ and $RY$ gates, and explore the effects of an entanglement stage within the mixing operator. Our results consistently show that SHC-RR outperforms LS approaches, showcasing superior efficacy despite its ostensibly simpler optimization mechanism. Furthermore, we observe that the inclusion of entanglement stages within mixing operators significantly impacts model performance, either enhancing or diminishing results depending on the specific problem context.

quant-ph↗
arXiv2023

PCA and t-SNE analysis in the study of QAOA entangled and non-entangled mixing operators

In this paper, we employ PCA and t-SNE analysis to gain deeper insights into the behavior of entangled and non-entangled mixing operators within the Quantum Approximate Optimization Algorithm (QAOA) at varying depths. Our study utilizes a dataset of parameters generated for max-cut problems using the Stochastic Hill Climbing with Random Restarts optimization method in QAOA. Specifically, we examine the $RZ$, $RX$, and $RY$ parameters within QAOA models at depths of $1L$, $2L$, and $3L$, both with and without an entanglement stage inside the mixing operator. The results reveal distinct behaviors when we process the final parameters of each set of experiments with PCA and t-SNE, where in particular, entangled QAOA models with $2L$ and $3L$ present an increase in the amount of information that can be preserved in the mapping. Furthermore, certain entangled QAOA graphs exhibit clustering effects in both PCA and t-SNE. Overall, the mapping results clearly demonstrate a discernible difference between entangled and non-entangled models, quantified numerically through explained variance in PCA and Kullback-Leibler divergence (after optimization) in t-SNE, where some of these differences are also visually evident in the mapping data produced by both methods.

quant-ph↗
arXiv2022

Quantum version of the k-NN classifier based on a quantum sorting algorithm

In this work we introduce a quantum sorting algorithm with adaptable requirements of memory and circuit depth, and then use it to develop a new quantum version of the classical machine learning algorithm known as k-nearest neighbors (k-NN). Both the efficiency and performance of this new quantum version of the k-NN algorithm are compared to those of the classical k-NN and another quantum version proposed by Schuld et al. \cite{Int13}. Results show that the efficiency of both quantum algorithms is similar to each other and superior to that of the classical algorithm. On the other hand, the performance of our proposed quantum k-NN algorithm is superior to the one proposed by Schuld et al. and similar to that of the classical k-NN.

quant-ph↗
arXiv2020

Image Classification via Quantum Machine Learning

Quantum Computing and especially Quantum Machine Learning, in a short period of time, has gained a lot of interest through research groups around the world. This can be seen in the increasing number of proposed models for pattern classification applying quantum principles to a certain degree. Despise the increasing volume of models, there is a void in testing these models on real datasets and not only on synthetic ones. The objective of this work is to classify patterns with binary attributes using a quantum classifier. Specially, we show results of a complete quantum classifier applied to image datasets. The experiments show favorable output while dealing with balanced classification problems as well as with imbalanced classes where the minority class is the most relevant. This is promising in medical areas, where usually the important class is also the minority class.

quant-ph↗
arXiv2019

Tetrapartite entanglement features of W-Class state in uniform acceleration

Using the single-mode approximation, we first calculate entanglement measures such as negativity ($1-3$ and $1-1$ tangles) and von Neumann entropy for a tetrapartite W-Class system in noninertial frame and then analyze the whole entanglement measures, the residual $π_{4}$ and geometric $Π_{4}$ average of tangles. Notice that the difference between $π_{4}$ and $Π_{4}$ is very small or disappears with the increasing accelerated observers. The entanglement properties are compared among the different cases from one accelerated observer to four accelerated observers. The results show that there still exists entanglement for the complete system even when acceleration $r$ tends to infinity. The degree of entanglement is disappeared for the $1-1$ tangle case when the acceleration $r > 0. 472473$. We reexamine the Unruh effect in noninertial frames. It is shown that the entanglement system in which only one qubit is accelerated is more robust than those entangled systems in which two or three or four qubits are accelerated. It is also found that the von Neumann entropy $S$ of the total system always increases with the increasing accelerated observers, but the $S_{κξ}$ and $S_{κζδ}$ with two and three involved noninertial qubits first {\it increases} and then {\it decreases} with the acceleration parameter $r$, but they are equal to constants $1$ and $0. 811278$ respectively for zero involved noninertial qubit.

quant-ph↗
arXiv2018

Application of Flexible Presentation of Quantum Images in Multipartite Correlations

We apply quantum model inspired on the classical Bayesian method also called mutual information to study the multipartite correlation in quantum images by using the flexible representation of quantum images (FRQI). This can be reflected by considering von Neumann entropy. The results are compared between two images of size $2\times 2$ and $8\times 8$ from different classical and quantum methods. We find that the classical joint entropy is invariant under transformation of change of color but the quantum entropy is sensitive to this change. It is shown that the total correlation $I_T$ could arrive to the double amount of the classical joint entropy.

quant-ph↗
arXiv2018

Tetrapartite entanglement measures of W-Class in noninertial frames

We present the entanglement measures of a tetrapartite W-Class entangled system in noninertial frame, where the transformation between Minkowski and Rindler coordinates is applied. Two cases are considered. First, when one qubit has uniform acceleration whilst the other three remain stationary. Second, when two qubits have nonuniform accelerations and the others stay inertial. The $1-1$ tangle, $1-3$ tangle and whole entanglement measurements ($π_4$ and $Π_4$), are studied and illustrated with graphics through their dependency on the acceleration parameter $r_d$ for the first case and $r_c$ and $r_d$ for the second case. It is found that the Negativities ($1-1$ tangle and $1-3$ tangle) and $π$-tangle decrease when the acceleration parameter $r_{d}$ or in the second case $r_c$ and $r_d$ increase, remaining a nonzero entanglement in the majority of the results. This means that the system will be always entangled except for special cases. It is shown that only the $1-1$ tangle for the first case, vanishes at infinite accelerations, but for the second case the $1-1$ tangle disappears completely when $r>0.472473$. It is found an analytical expression for von Neumann information entropy of the system and we notice that it increases with the acceleration parameter.

quant-ph↗
arXiv2018

Semi-exact solutions of the Razavy potential

In this work we study the quantum system with the symmetric Razavy potential and show how to find its exact solutions. We find that the solutions are given by the confluent Heun functions. The eigenvalues have to be calculated numerically. The properties of the wave functions depending on $m$ are illustrated graphically for a given potential parameter $ξ$. We find that the even and odd wave functions with definite parity are changed to odd and even wave functions when the potential parameter $m$ increases. This arises from the fact that the parity, which is a defined symmetry for very small $m$, is completely violated for large $m$. We also notice that the energy levels $ε_{i}$ decrease with the increasing potential parameter $m$.

quant-ph↗
arXiv2017

Constructions of the soluble potentials for the non-relativistic quantum system by means of the Heun functions

The Schrödinger equation $ψ"(x)+κ^2 ψ(x)=0$ where $κ^2=k^2-V(x)$ is rewritten as a more popular form of a second order differential equation through taking a similarity transformation $ψ(z)=ϕ(z)u(z)$ with $z=z(x)$. The Schrödinger invariant $I_{S}(x)$ can be calculated directly by the Schwarzian derivative $\{z, x\}$ and the invariant $I(z)$ of the differential equation $u_{zz}+f(z)u_{z}+g(z)u=0$. We find an important relation for moving particle as $\nabla^2=-I_{S}(x)$ and thus explain the reason why the Schrödinger invariant $I_{S}(x)$ keeps constant. As an illustration, we take the typical Heun differential equation as an object to construct a class of soluble potentials and generalize the previous results through choosing different $ρ=z'(x)$ as before. We get a more general solution $z(x)$ through integrating $(z')^2=α_{1}z^2+β_{1}z+γ_{1}$ directly and it includes all possibilities for those parameters. Some particular cases are discussed in detail.

quant-ph↗
arXiv2017

Quantum teleportation and information splitting via four-qubit cluster state and a Bell state

Quantum teleportation provides a `bodiless' way of transmitting the quantum state from one object to another, at a distant location, using a classical communication channel and a previously shared entangled state. In this paper, we present a tripartite scheme for probabilistic teleportation of an arbitrary single qubit state, without losing the information of the state being teleported, via a four-qubit cluster state of the form $\left.|ϕ\right\rangle_{1234}=\left.α|0000\right\rangle+\left.β|1010\right\rangle+\left.γ|0101\right\rangle-η\left.|1111\right\rangle$, as the quantum channel, where the nonzero real numbers $α$, $β$, $γ$, and $η$ satisfy the relation $|α|^2+|β|^2+|γ|^2+|η|^2=1$. With the introduction of an auxiliary qubit with state $\left|0\right\rangle$, using a suitable unitary transformation and a positive-operator valued measure (POVM), the receiver can recreate the state of the original qubit. An important advantage of the teleportation scheme demonstrated here is that, if the teleportation fails, it can be repeated without teleporting copies of the unknown quantum state, if the concerned parties share another pair of entangled qubit. We also present a protocol for quantum information splitting of an arbitrary two-particle system via the aforementioned cluster state and a Bell-state as the quantum channel. Problems related to security attacks were examined for both the cases and it was found that this protocol is secure. This protocol is highly efficient and easy to implement.

quant-ph↗
arXiv2016

Teleportation with two-dimensional electron gas formed at the interface of a GaAs heterostructure

Inspired by the scenario by Bennett et al., a teleportation protocol of qubits formed in a two-dimensional electron gas formed at the interface of a GaAs heterostructure is presented. The teleportation is carried out using three GaAs quantum dots (say $\mathcal{P}\mathcal{P}'$, $\mathcal{Q}\mathcal{Q}'$, $\mathcal{R}\mathcal{R}'$) and three electrons. The electron spin on GaAs quantum dots $\mathcal{P}\mathcal{P}'$ is used to encode the unknown qubit. The GaAs quantum dot $\mathcal{Q}\mathcal{Q}'$ and $\mathcal{R}\mathcal{R}'$ combine to form {an} entangled state. Alice (the sender) performs a Bell measurement on pairs ($\mathcal{P},\mathcal{Q}$) and ($\mathcal{P}',\mathcal{Q}'$). Depending on the outcome of {the} measurement, a suitable Hamiltonian for the quantum gate can be used by Bob (receiver) to transform the information based on {a} spin to charge-based information. This work offers relevant corrections to misconception in {\it Chem. Phys. Lett. {\bf421} (2006) 338.

quant-ph↗