arXiv subjects

Kemal Bidzhiev

Publications and source records attributed to Kemal Bidzhiev.

12 recordsLinked to original sources

arXiv2026

Noise-aware emulation and cross-device validation of neutral atom analog quantum processing units

Analog quantum processors based on Rydberg atom arrays are a powerful platform for many-body quantum simulation, combinatorial optimization, and graph machine learning. As these devices become increasingly accessible, establishing confidence in their outputs requires predictive models that quantitatively connect microscopic hardware imperfections to empirical results. Here, we present a noise-aware emulation framework that propagates the dominant noise mechanisms throughout the full computation cycle to predict device behavior. We validate the framework by benchmarking two representative protocols, quantum annealing and post-quench dynamics, on three Pasqal quantum processors where classical simulations still provide ground truth. Across all three devices, the measured observables fall within the uncertainty envelopes predicted by the emulator. Beyond reproducing the data, the framework isolates which physical mechanism dominates in each operating regime, provides quantitative guidance for algorithm design and hardware improvements, and establishes a foundation for verifying analog processors in regimes beyond classical reach.

quant-ph↗

arXiv2025

Resource assessment of classical and quantum hardware for post-quench dynamics

We estimate the run-time and energy consumption of simulating non-equilibrium dynamics on neutral atom quantum computers in analog mode, directly comparing their performance to state-of-the-art classical methods, namely Matrix Product States and Neural Quantum States. By collecting both experimental data from a quantum processing unit (QPU) in analog mode and numerical benchmarks, we enable accurate predictions of run-time and energy consumption for large-scale simulations on both QPUs and classical systems through fitting of theoretical scaling laws. Our analysis shows that neutral atom devices are already operating in a competitive regime, achieving comparable or superior performance to classical approaches while consuming significantly less energy. These results demonstrate the potential of analog neutral atom quantum computing for energy-efficient simulation and highlight a viable path toward sustainable computational strategies.

quant-ph↗

arXiv2025

Simulating dynamics of the two-dimensional transverse-field Ising model: a comparative study of large-scale classical numerics

The quantum dynamics of many-qubit systems is an outstanding problem that has recently driven significant advances in both numerical methods and programmable quantum processing units. In this work, we employ a comprehensive toolbox of state-of-the-art numerical approaches to classically simulate the dynamics of the two-dimensional transverse field Ising model. Our methods include three different tensor network techniques -- matrix product states, tree-tensor networks, and two-dimensional tensor-networks under the belief propagation approximation -- as well as time-dependent variational Monte Carlo with Neural Quantum States. We focus on two paradigmatic dynamical protocols: (i) quantum annealing through a critical point and (ii) post-quench dynamics. Our extensive results show the quantitative predictions of various state-of-the-art numerical methods providing a benchmark for future numerical investigations and experimental studies with the aim to push the limitations on classical and QPUs. In particular, our work connects classical simulability to different regimes associated with quantum dynamics in Rydberg arrays - namely, quasi-adiabatic dynamics, the Kibble-Zurek mechanism, and quantum quenches.

quant-ph↗

arXiv2025

Efficient Emulation of Neutral Atom Quantum Hardware

Simulating the dynamics of neutral atom arrays is a challenging problem. To address this, we introduce two emulators, emu-sv and emu-mps, as computational backends for Pasqal's pulser package. Emu-sv is designed for high-precision state-vector simulations, giving the possibility to emulate systems of up to $\thicksim 27$ qubits on an A100 40GB GPU, making it perfect for cases where numerically exact results are needed. In contrast, emu-mps uses a Matrix Product State representation and other controlled approximations to efficiently simulate much larger arrays of atoms with manageable errors. We show through benchmark comparisons that both emulators provide significant speed-ups over generic solvers such as QuTiP. In addition, we provide practical guidance on choosing between the two emulators. These quantum software tools are designed to support researchers and developers aiming to simulate quantum systems either as a precursor to full hardware implementation or as a means of benchmarking hardware performance.

quant-ph↗

arXiv2023

Emergence of anyonic correlations from spin and charge dynamics in one dimension

We propose a transformation for spin and charge degrees of freedom in one-dimensional lattice systems, constrained to have no doubly occupied sites, that allows direct access to the dynamical correlations of the system. The transformation delivers particle creation and annihilation operators in a form of a spinless particle and a non-local operator acting on the space of states of a spin-$1/2$ chain. This permits a decomposition of dynamical correlation functions as a convolution of those for impenetrable anyons together with those of a spin chain. Further analysis can be done by methods tailored for each part of the convolution, greatly increasing the impact and flexibility of the approach.

cond-mat.quant-gas↗

arXiv2023

Cloud on-demand emulation of quantum dynamics with tensor networks

We introduce a tensor network based emulator, simulating a programmable analog quantum processing unit (QPU). The software package is fully integrated in a cloud platform providing a common interface for executing jobs on a HPC cluster as well as dispatching them to a QPU device. We also present typical emulation use cases in the context of Neutral Atom Quantum Processors, such as evaluating the quality of a state preparation pulse sequence, and solving Maximum Independent Set problems by applying a parallel sweep over a set of input pulse parameter values, for systems composed of a large number of qubits.

quant-ph↗

arXiv2021

Macroscopic effects of localised measurements in jammed states of quantum spin chains

A quantum jammed state can be seen as a state where the phase space available to particles shrinks to zero, an interpretation quite accurate in integrable systems, where stable quasiparticles scatter elastically. We consider the integrable dual folded XXZ model, which is equivalent to the XXZ model in the limit of large anisotropy. We perform a jamming-breaking localised measurement in a jammed state. We find that jamming is locally restored, but local observables exhibit nontrivial time evolution on macroscopic, ballistic scales, without ever relaxing back to their initial values.

cond-mat.stat-mech↗

arXiv2021

Measurement catastrophe and ballistic spread of charge density with vanishing current

One of the features of many-body quantum systems with Hilbert-space fragmentation is the existence of stationary states manifesting quantum jamming. It was recently shown that these are "states with memory", in which, e.g., measuring a localised observable has everlasting macroscopic effects. We study such a measurement catastrophe with an example that stands out for its clarity. We show in particular that at late times the expectation value of a charge density becomes a nontrivial function of the ratio between distance and time notwithstanding the corresponding current approaching zero.

quant-ph↗

arXiv2021

The Folded Spin-1/2 XXZ Model: II. Thermodynamics and Hydrodynamics with a Minimal Set of Charges

We study the (dual) folded spin-1/2 XXZ model in the thermodynamic limit. We focus, in particular, on a class of local macrostates that includes Gibbs ensembles. We develop a thermodynamic Bethe Ansatz description and work out generalised hydrodynamics at the leading order. Remarkably, in the ballistic scaling limit the junction of two local macrostates results in a discontinuity in the profile of essentially any local observable.

cond-mat.stat-mech↗

arXiv2020

Non-Hermitian quantum impurity systems in and out of equilibrium: noninteracting case

We provide systematic analysis on a non-Hermitian PT -symmetric quantum impurity system both in and out of equilibrium, based on exact computations. In order to understand the interplay between non-Hermiticity and Kondo physics, we focus on a prototypical noninteracting impurity system, the resonant level model, with complex coupling constants. Explicitly constructing biorthogonal basis, we study its thermodynamic properties as well as the Loschmidt echo starting from the initially disconnected two free fermion chains. Remarkably, we observe the universal crossover physics in the Loschmidt echo, both in the PT broken and unbroken regimes. We also find that the ground state quantities we compute in the PT broken regime can be obtained by analytic continuation. It turns out that Kondo screening ceases to exist in the PT broken regime, which was also previously predicted in the non-hermitian Kondo model. All the analytical results are corroborated against biorthogonal free fermion numerics.

cond-mat.stat-mech↗

arXiv2019

Out-of-equilibrium transport in the interacting resonant level model: the surprising relevance of the boundary sine-Gordon model

Using time-dependent density matrix renormalization group calculations we study the transport properties ($I-V$ curves and shot noise) of the interacting resonant level model (IRLM) in a large range of the interaction parameter $U$, in the scaling limit. We find that these properties can be described remarkably well by those of the Boundary sine-Gordon model (BSG), which are known analytically (Fendley, Ludwig and Saleur, 1995). We argue that the two models are nevertheless in different universality classes out of equilibrium: this requires a delicate discussion of their infra-red (IR) properties ({\it i.e.} at low voltage), where we prove in particular that the effective tunneling charge is $e$ in the infra-red regime of the IRLM (except at the self-dual point where it jumps to $2e$), while it is known to be a continuously varying function of $U$ in the BSG. This behavior is confirmed by careful analysis of the numerical data in the IR. The remarkable agreement of the transport properties, especially in the crossover region, remains however unexplained.

cond-mat.str-el↗

arXiv2017

Out-of-equilibrium dynamics in a quantum impurity model: numerics for particle transport and entanglement entropy

We investigate the out-of-equilibrium properties of a simple quantum impurity model, the interacting resonant level model (IRLM). We focus on the scaling regime, where the bandwidth of the fermions in the leads is larger than all the other energies, so that the lattice and the continuum versions of the model become equivalent. Using time-dependent DMRG simulations initialized with states having different densities in the two leads we extend the results of Boulat, Saleur and Schmitteckert [Phys. Rev. Lett. 101, 140601 (2008)] concerning the current-voltage ($I$-$V$) curves, for several values of the interaction strength $U$. We estimate numerically the Kondo scale $T_B$ and the exponent $b(U)$ associated to the tunneling of the fermions from the leads to the dot. Next we analyze the quantum entanglement properties of the steady states. We focus in particular on the entropy rate $α$, describing the linear growth with time of the bipartite entanglement in the system. We show that, as for the current, $α/T_B$ is described by some function of $U$ and of the rescaled bias $V/T_B$. Finally, the spatial structure of the entropy profiles is discussed.

cond-mat.str-el↗