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Sagastizabal, R.E. (author)Superconducting qubits have seen a tremendous progress in the last two decades, and yet they remain unable to extract quantum advantage for application scenarios. While algorithms like Shorâ€™s demonstrate quantum advantage in theory, they do not seem to fit modern noisy quantum processors. Then, in order to achieve quantum advantage either modern...doctoral thesis 2023
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Ubbens, Otmar (author)Crucial to the behaviour of a NitrogenVacancy (NV) centre are its excited state cyclicities, determining the ability to perform high fidelity readout, spinphoton entanglement generation or fast spinpumping. This work presents a unified model to predict these excited state cyclicities over a wide range of strain, electric field, magnetic field...master thesis 2022
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SAMIOTIS, MARIOS (author)In this work, we first analyse a theoretical technique based on entropic inequalities, which in principle can be used to compare classical and quantum algorithms running on noisy quantum devices. The technique has been used in the past for depolarizing noise, and has shown that for NISQ variational quantum algorithms (VQAs) to give an advantage...master thesis 2022
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van Diepen, C.J. (author)More is more applies in particular to systems with interacting parts. These interactions enable the emergence of collective behaviour. Examples can be found among the behaviour of animals, such as the Vshaped formation of migrating geese and the flight of a flock of starlings. More examples are found among the electromagnetic properties of...doctoral thesis 2021
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Stroeks, Maarten (author)Quantum systems are in general not e_ciently simulatable by classical means. If one wishes to determine (some of) the eigenvalues of a Hamiltonian H that is associated with a quantum system, there are two favoured strategies: Quantum simulation and quantum Monte Carlo schemes. The former strategy uses an experimentally wellcontrollable quantum...master thesis 2020
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Mukhopadhyay, U. (author)We are entering the era of the second quantum revolution, where we aim to harness the power of quantum mechanics to create new technologies. Quantum technologies have the potential to revolutionize the fields of simulation, computation, communication, sensing, metrology, and many others. Here we discuss analog quantum simulation, which has...doctoral thesis 2019
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Ubbens, Otmar (author)With the rapid development of Quantum Computers (QC) and QC Simulators, there will be an increased demand for functioning Quantum Algorithms in the near future. Some of the most ubiquitously useful algorithms are solvers for linear systems of equations. Since the conception of the Quantum Linear Solver Algorithm (QLSA) by Harrow, Hassidim and...bachelor thesis 2019
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O'Brien, T.E. (author), Tarasinski, B.M. (author), Terhal, B.M. (author)Quantum phase estimation (QPE) is the workhorse behind any quantum algorithm and a promising method for determining ground state energies of strongly correlated quantum systems. Lowcost QPE techniques make use of circuits which only use a single ancilla qubit, requiring classical postprocessing to extract eigenvalue details of the system....journal article 2019
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Steudtner, M. (author), Wehner, S.D.C. (author)Quantum simulation of fermionic systems is a promising application of quantum computers, but to program them, we need to map fermionic states and operators to qubit states and quantum gates. While quantum processors may be built as twodimensional qubit networks with couplings between nearest neighbors, standard fermionToqubit mappings do...journal article 2019
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Mezzacapo, A. (author), Las Heras, U. (author), Pedernales, J.S. (author), Di Carlo, L. (author), Solano, E. (author), Lamata, L. (author)We propose the analogdigital quantum simulation of the quantum Rabi and Dicke models using circuit quantum electrodynamics (QED). We find that all physical regimes, in particular those which are impossible to realize in typical cavity QED setups, can be simulated via unitary decomposition into digital steps. Furthermore, we show the emergence...journal article 2014
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Barthelemy, P.J.C. (author), Vandersypen, L.M.K. (author)Quantum mechanics often results in extremely complex phenomena, especially when the quantum system under consideration is composed of many interacting particles. The states of these manybody systems live in a space so large that classical numerical calculations cannot compute them. Quantum simulations can be used to overcome this problem:...journal article 2013