Search · four archives
Search · four archives
15 papers · ranked by Valyu relevance
Harper R. Grimsley, Sophia E. Economou, Edwin Barnes, Nicholas J. Mayhall
'Nicholas J. Mayhall'] Quantum simulation of chemical systems is one of the most promising near-term applications of quantum computers. The variational quantum eigensolver, a leading algorithm for molecular simulations on quantum hardware, has a serious limitation in that it typically relies on a pre-selected…
Suguru Endo, Zhenyu Cai, Simon C. Benjamin, Xiao Yuan
Quantum computers can exploit a Hilbert space whose dimension increases exponentially with the number of qubits. In experiment, quantum supremacy has recently been achieved by the Google team by using a noisy intermediate-scale quantum (NISQ) device with over 50 qubits. However, the question of what can be implemented…
Lihui Lv, Bao Yan, Hong Wang, Zhi Ma + 5 more
'Qianheng Duan' 'Brian R. La Cour' 'Giuliano Benenti'] The variational quantum algorithm (VQA) is a hybrid classical-quantum algorithm. It can actually run in an intermediate-scale quantum device where the number of available qubits is too limited to perform quantum error correction, so it is one of the most promising…
Suguru Endo, Jinzhao Sun, Ying Li, Simon C. Benjamin + 1 more
Variational quantum algorithms have been proposed to solve static and dynamic problems of closed many-body quantum systems. Here we investigate variational quantum simulation of three general types of tasks—generalised time evolution with a non-Hermitian Hamiltonian, linear algebra problems, and open quantum system…
Benedikt Fauseweh
Simulating quantum many-body systems is a key application for emerging quantum processors. While analog quantum simulation has already demonstrated quantum advantage, its digital counterpart has recently become the focus of intense research interest due to the availability of devices that aim to realize general-purpose…
Robert J. P. T. de Keijzer, Luke Y. Visser, Oliver Tse, Servaas J. J. M. F. Kokkelmans
We report an algorithm that is able to tailor qubit interactions for individual variational quantum algorithm problems. The algorithm leverages the unique ability of a neutral atom tweezer platform to realize arbitrary qubit position configurations. These configurations determine the degree of entanglement available to…
Juan Carlos Garcia‐Escartin
> This paper presents a hybrid variational quantum algorithm that finds a random eigenvector of a unitary matrix with a known quantum circuit. The algorithm is based on the SWAP test on trial states generated by a parametrized quantum circuit. The eigenvector is described by a compact set of classical parameters that…
Fong Yew Leong, Wei-Bin Ewe, Dax Enshan Koh
Variational quantum algorithms offer a promising new paradigm for solving partial differential equations on near-term quantum computers. Here, we propose a variational quantum algorithm for solving a general evolution equation through implicit time-stepping of the Laplacian operator. The use of encoded source states…
Sayantan Pramanik, Chaitanya Murti, M. Girish Chandra
Variational quantum circuits characterise the state of a quantum system through the use of parameters that are optimised using classical optimisation procedures that typically rely on gradient information. The circuit-execution complexity of estimating the gradient of expectation values grows linearly with the number…
Kang-Min Hu, Min Namkung, Hyang-Tag Lim
Quantum computers have the potential to deliver speed-ups for solving certain important problems that are intractable for classical counterparts, making them a promising avenue for advancing modern computation. However, many quantum algorithms require deep quantum circuits, which are challenging to implement on current…
Ronghang Chen, Shi‐Yao Hou, Cong Guo, Guanru Feng
Optimization problems are prevalent in various fields, and the gradient-based gradient descent algorithm is a widely adopted optimization method. However, in classical computing, computing the numerical gradient for a function with d variables necessitates at least d+1 function evaluations, resulting in a computational…
Tasneem M Watad, Netanel H. Lindner
We introduce a variational hybrid classical-quantum algorithm to simulate the Lindblad master equation and its adjoint for time-evolving Markovian open quantum systems and quantum observables. Our method is based on a direct representation of density matrices and quantum observables as quantum superstates. We design…
Chenyu Shi, Vedran Dunjko, Hao Wang
Variational quantum eigensolver (VQE) is one of the most prominent algorithms using near-term quantum devices, designed to find the ground state of a Hamiltonian. In VQE, a classical optimizer iteratively updates the parameters in the quantum circuit. Among various optimization methods, quantum natural gradient descent…
Ijaz Ahamed Mohammad, Matej Pivoluska, Martin Plesch
The current state of quantum computing is commonly described as the Noisy Intermediate-Scale Quantum era. Available computers contain a few dozens of qubits and can perform a few dozens of operations before the inevitable noise erases all information encoded in the calculation. Even if the technology advances fast…
Ruilin Liu, Sebastián V. Romero, Izaskun Oregi, Eneko Osaba + 3 more
'Esther Villar-Rodriguez' 'Yue Ban' 'Xi Chen'] Coherent states, known as displaced vacuum states, play an important role in quantum information processing, quantum machine learning, and quantum optics. In this article, two ways to digitally prepare coherent states in quantum circuits are introduced. First, we construct…