Quantum computing is emerging as a transformative paradigm for molecular-level modeling in process engineering, offering the potential to perform large-scale, high-accuracy simulations that surpass the computational limits of classical methods. However, the inherent noise and decoherence in quantum systems present major obstacles to reliable molecular interaction predictions. This research conducts a qualitative investigation of error-mitigation strategies designed to improve the accuracy and stability of quantum simulations for modeling molecular interactions relevant to chemical and process engineering. By reviewing scientific literature and analyzing case studies across quantum mechanics, computational chemistry, and industrial process modeling, the study identifies the principal challenges associated with quantum noise, gate fidelity, and algorithmic scalability. A conceptual framework was developed to evaluate how quantum error correction (QEC) techniques, zero-noise extrapolation, and hybrid quantum–classical algorithms enhance predictive precision in molecular simulations. The findings suggest that combining these methods not only mitigates computational noise but also improves convergence efficiency in modeling reaction pathways and intermolecular potentials. This research synthesizes interdisciplinary insights to propose a roadmap for integrating quantum-enhanced molecular simulations into sustainable process engineering. It underscores how advances in error mitigation will be essential for achieving trustworthy, energy-efficient, and scalable industrial applications of quantum computation in the coming decade.
Quantum computing is emerging as a transformative paradigm for molecular-level modeling in process engineering, offering the potential to perform large-scale, high-accuracy simulations that surpass the computational limits of classical methods. However, the inherent noise and decoherence in quantum systems present major obstacles to reliable molecular interaction predictions. This research conducts a qualitative investigation of error-mitigation strategies designed to improve the accuracy and stability of quantum simulations for modeling molecular interactions relevant to chemical and process engineering. By reviewing scientific literature and analyzing case studies across quantum mechanics, computational chemistry, and industrial process modeling, the study identifies the principal challenges associated with quantum noise, gate fidelity, and algorithmic scalability. A conceptual framework was developed to evaluate how quantum error correction (QEC) techniques, zero-noise extrapolation, and hybrid quantum–classical algorithms enhance predictive precision in molecular simulations. The findings suggest that combining these methods not only mitigates computational noise but also improves convergence efficiency in modeling reaction pathways and intermolecular potentials. This research synthesizes interdisciplinary insights to propose a roadmap for integrating quantum-enhanced molecular simulations into sustainable process engineering. It underscores how advances in error mitigation will be essential for achieving trustworthy, energy-efficient, and scalable industrial applications of quantum computation in the coming decade.
Accurate prediction of molecular structures and properties is vital for chemistry; materials science, and drug discovery, yet classical electronic-structure methods often fail for strongly correlated systems, large basis sets, and complex potential-energy landscapes. Quantum technology encompassing quantum computing, quantum machine learning, and hybrid quantum classical strategies offers a fundamentally new paradigm by encoding many-electron wave functions directly on qubits and exploiting superposition and entanglement to explore exponentially large Hilbert spaces. This review synthesizes recent algorithmic and hardware advances relevant to molecular modelling, including the Variational Quantum Eigensolver (VQE), Quantum Phase Estimation (QPE), quantum unitary coupled-cluster (q-UCC) families, equation-of-motion and subspace methods for excited states, tensor-network hybrids, and quantum kernel and variational QML approaches. We examine noise-aware hybrid workflows, error-mitigation techniques, symmetry-preserving ansätze, and operator-factorization methods that reduce measurement and gate overhead. Representative applications are discussed: ground- and excited-state energy prediction, potential-energy surface mapping, geometry and transition-state optimization, spectroscopic property estimation (IR, UV–Vis, NMR, EPR), and reaction-dynamics scenarios where non-adiabatic effects and conical intersections dominate. Resource estimates and scaling analyses clarify current NISQ limitations qubit counts, circuit depth, shot complexity and delineate the roadmap to fault-tolerant QPE for chemical accuracy. We compare quantum approaches with classical baselines (DFT, CCSD (T), multireference methods), identifying domains where quantum methods already show promise (strong correlation, multi-reference dissociation, spin-state ordering) and where classical methods remain competitive. Finally, we highlight near-term industrial opportunities in drug design, catalysis, CO2 capture, and energy materials, and outline critical research directions: algorithmic reductions in measurement/precision cost, hardware improvements in fidelity and connectivity, scalable ansatz design, and integrated software stacks for reproducible hybrid simulations. Together, these developments indicate that while practical, large-scale quantum advantage for general chemistry remains future work, quantum technologies are rapidly maturing into powerful tools for targeted molecular problems that are intractable with existing classical techniques.
We explore the field of quantum computing and specifically address the crucial problem of error reduction in the context of IBM simulators. Although quantum computing is a rapidly developing technology with great potential, its practical applications are severely hindered by its inherent error-proneness. We tackle this problem by introducing new developments in quantum error correction techniques designed for IBM simulators. In contrast to conventional methods that frequently depend on large matrices or pre-established error models; our technique presents a flexible and dynamic approach. By utilizing several variations of a main circuit, in which classically efficient gates are used in place of non-Clifford gates, we are able to discover the best compensation scheme from scratch for actual quantum systems. The suggested method exhibits great flexibility in handling different levels of noise and different kinds of noise, such as spatially and temporally correlated variations. It also effectively reduces errors on IBM quantum hardware as well as precisely emulated imperfect quantum computers. By offering a thorough investigation of sophisticated error mitigation techniques, this research advances the continuing quest for dependable quantum computations and opens up interesting new directions for improving both the accuracy and performance of quantum computing operations carried out on IBM simulators.
The advancements in classical computational components such as CPUs and GPUs have had a reverberating impact on the democratization of computational power available, with the field of computational chemistry reaping significant benefits from the propulsion of the limits of systems studied. The accurate prediction of chemical properties and reaction dynamics through computational simulation is now a centerpiece of modern chemical research, significantly accelerating discoveries research areas of materials science and drug development, as well as industrially relevant processes such as the emission of aldehydes from soft foams, flame retardants and pyrolysis and the carbonylation of epoxides. These achievements of computational chemistry still are overshadowed in the face of fundamental bottlenecks where classical methods remain constrained by the exponential scaling when treating large and/or strongly correlated quantum many-body systems. This innate computational complexity often constitutes chemically accurate calculations based on first principles impractical, or plain impossible, for systems beyond modest sizes. Quantum computing offers a potential pathway around these limitations, originally formally formulated by David Deutsch as a tool for simulating quantum systems, with the first quantum algorithms indicating speed-ups compared to classical counterparts arising from Peter Shor and Lov Grover for the prime factorization of an integer number and unstructured search respectively. Relying on fundamental theorems by Claude Shannon, it has been demonstrated that through the use of error-correcting codes fault-tolerant quantum computers are able to safeguard information against noise and decoherence, strongly indicating towards exponential speedups in solving central computational chemistry problems, such as determining ground state energies or reaction pathways of chemical systems. Substantial strides in experimental quantum computing over the past decade, including proof-of-principle demonstrations of quantum error correction, mean to bring full-scale fault-tolerant quantum computing within the grasp of humanity. The breakthroughs needed to attain scalable, error-corrected quantum computation with capabilities exceeding those of classical methods in real-world scenarios is likely still some years away. While striving to address the engineering challenges standing in the way of achieving fault tolerant quantum computing, substantial effort has been focused toward developing and benchmarking hybrid algorithms tailored for the Noisy Intermediate- Scale Quantum (NISQ) devices, available now to researchers. These hybrid quantum-classical algorithms, with the most notable being the Variational Quantum Eigensolver (VQE), allow the probing of quantum computing’s utility in computational chemistry even in the face of significant hardware noise and limited coherence times. The work presented in this thesis introduces several key additions the VQE framework, geared especially towards to NISQ hardware, where the mindful use of available resources is imperative. First, the implementation of the Conjugate Model Search optimizer is described, an optimization method that integrates simple models that are surrogate to the original function, combined with conjugate gradient optimization to navigate effectively parameter landscapes typical of variational algorithms, prone to noise. Second, this thesis contains the proposal and extensive study of a hyperparameter tuning procedure employing genetic algorithms, allowing for comprehensive simulation benchmarks that augment the robustness and efficiency of VQE implementations with respect to convergence time through real wall-time models of quantum processors. Continuing, a bridge is presented between quantum simulation and quantum chemistry, through qubit-to-fermion mappings of existing quantum gates, further enabling the direct and accurate modeling of chemical systems on trapped atom quantum hardware with the added arsenal provided by techniques designed for qubit architectures. Additionally, experimental data contained in this thesis include detailed benchmarking data collected from state-of-the-art trapped ion quantum processors available at the Johannes Gutenberg Universität Mainz, demonstrating the actual viability and performance of various methodologies for extracting results. Lastly, the state of VQE is examined, as it served as a springboard for a plethora of advancements in the development of quantum computing hardware, as well as the direction the field of simulation of computational quantum chemistry via quantum devices is headed towards in the coming years.
The integration of quantum optimization techniques into chemical engineering has emerged as a frontier in achieving more efficient, sustainable, and adaptive process design. This study presents a qualitative investigation into the role of multi-objective quantum optimization frameworks for enhancing process intensification in next-generation chemical plants. The research explores how quantum-inspired algorithms—leveraging quantum superposition, entanglement, and probabilistic search mechanisms—can optimize multiple competing objectives such as energy consumption, production throughput, and environmental impact simultaneously. Through a comprehensive review of both academic and industrial literature, the study identifies key trends in the use of hybrid quantum–classical models for solving high-dimensional optimization problems in chemical plant design and operation. It examines how quantum-assisted methods, including the Quantum Approximate Optimization Algorithm (QAOA) and Variational Quantum Eigensolver (VQE), can accelerate simulation convergence and decision-making in process systems engineering. The qualitative findings underscore the transformative potential of quantum-enhanced computation in enabling process intensification, where chemical operations are redesigned for maximum efficiency and minimal ecological footprint. Furthermore, this research analyzes the interdisciplinary interface between quantum computing, chemical engineering, and sustainable manufacturing, emphasizing how algorithmic innovation can support cleaner, more resource-efficient production ecosystems. Conceptual models were developed to illustrate the role of quantum optimization in guiding strategic decisions related to resource allocation, system design, and environmental trade-offs. The study concludes that quantum optimization will likely become a cornerstone of the digital and sustainable transformation of the chemical industry, facilitating intelligent automation and data-driven sustainability in the decades ahead.
Quantum computing represents one of the most transformative technological developments of the twenty-first century. However, the practical realization of its potential on current Noisy Intermediate-Scale Quantum (NISQ) hardware remains severely constrained by noise and computational errors that arise from the inherent fragility of quantum states. This paper presents a systematic comparative analysis of three prominent quantum error mitigation techniques, partial quantum error correction (QEC), zero-noise extrapolation (ZNE), and deep learning-based noise prediction, and develops a predictive assessment of a proposed hybrid framework that integrates all three into a unified system. Through a thorough review of twelve peer-reviewed publications spanning 2017 to 2026, we establish what each technique has accomplished individually and to what degree of accuracy. We identify a critical and previously unaddressed gap: no existing work has systematically combined these three complementary approaches. Drawing on documented performance trends and theoretical complementarity, we predict that a well-designed hybrid framework could achieve classification accuracies of 85 to 90 percent on standard quantum machine learning benchmarks, compared to only 60 to 65 percent without error mitigation. These predictions are grounded in peer-reviewed experimental data. Our analysis provides a clear evidence-based roadmap for future experimental validation and establishes a strong foundation for the development of practical, resource-efficient quantum machine learning systems on near-term hardware. CCS Concepts: Hardware → Quantum computation; • Computing methodologies → Machine learning; • Theory of computation → Quantum complexity theory
Quantum computing holds the potential to address problems that are currently considered intractable for classical processors by leveraging quantum mechanical effects for simulation, optimization, and chemistry. Despite recent technological progress, quantum hardware remains in the noisy intermediate-scale regime, where coherence limits, gate imperfections, and readout errors restrict circuit depth and algorithmic reliability. Although first demonstrations of small-scale Quantum Error Correction exist, logical processors with low logical error rates are still distant. In the near term, even error-corrected qubits are expected to operate with residual error, which means that improving calibration and mitigating errors at the physical and circuit level will remain essential for obtaining meaningful results. Established calibration routines and mitigation methods such as Zero-Noise-Extrapolation (ZNE) are valuable, but need to be further improved and more rigorously validated with respect to their underlying assumptions, stability and quantitative benefits. This thesis addresses error reduction techniques on transmon qubits through calibration, gate analysis, and circuit-level mitigation. First, a systematic comparison of two single-qubit amplitude calibration techniques is carried out (cross-point and ping-pong calibration), followed by an analysis of two implementations of a two-qubit gate, based on the cross-resonance interaction. The results show that cross-point calibration offers faster convergence, higher precision and a more favorable signal to noise ratio than ping-pong calibration. Hamiltonian tomography confirms the validity of a reduced model for the cross-resonance interaction, and algorithmic tests reveal that direct and echoed CNOT gates offer complementary advantages depending on the application. Second, the thesis develops and evaluates the method of Inverted-Circuit Zero-Noise-Extrapolation (IC-ZNE). Its main idea consists of measuring the effective error strength of a circuit through inverted circuits. This quantity is then used for extrapolation towards zero noise rather than relying on simple, approximate noise scaling assumptions as in standard ZNE. This approach constitutes a novel and original method. IC-ZNE consistently produces results closer to ideal reference values than standard ZNE. The method achieves up to 77% error reduction in observable error on the tested circuits compared to standard ZNE and simple post processing filters can yield up to 39% reduction in selected cases compared to standard ZNE. Further refinements introduce noise-adaptive circuit scaling strategies that enhance mitigation outcomes without significant additional cost. The performance of these techniques is examined across several circuits and in the context of variational quantum algorithms. Applications to the Quantum Approximate Optimization Algorithm and the Variational Quantum Eigensolver demonstrate that these techniques extend the useful operating regime of current devices, although their effectiveness decreases for very deep circuits or unfavorable variational ansätze. Taken together, the calibration and mitigation techniques investigated and developed in this thesis demonstrate practical routes toward enhancing the reliability of near-term quantum processors. While they cannot replace full fault-tolerant quantum computation, they offer useful and complementary capabilities that support progress toward scalable quantum technologies.