Excitations of Quantum Many-Body Systems via Purified Ensembles: A Unitary-Coupled-Cluster-based Approach

• URL: http://arxiv.org/abs/2201.10974v2
• Date: Tue, 31 May 2022 12:25:30 GMT
• Title: Excitations of Quantum Many-Body Systems via Purified Ensembles: A Unitary-Coupled-Cluster-based Approach
• Abstract summary: State-average calculations based on mixture of states are increasingly being exploited across chemistry and physics. We show how the two approaches can be merged into one method, dealing with a generalized yet single pure state.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: State-average calculations based on mixture of states are increasingly being exploited across chemistry and physics as versatile procedures for addressing excitations of quantum many-body systems. If not too many states should need to be addressed, calculations performed on individual states is also a common option. Here we show how the two approaches can be merged into one method, dealing with a generalized yet single pure state. Implications in electronic structure calculations are discussed and for quantum computations are pointed out.

Related papers

• Unsupervised Learning to Recognize Quantum Phases of Matter [39.146761527401424]
  In this work we adopt unsupervised learning, where the algorithm has no access to any priorly labeled states.<n>We benchmark our method with two specific spin-$frac12$ chains, with states determined via tensor network techniques.<n>Our results show how unsupervised learning can autonomously recognize and possibly unveil novel phases of quantum matter.
  arXiv  Detail & Related papers  (2025-10-16T14:45:54Z)
• Quantum State Preparation Of Multiconfigurational States For Quantum Chemistry [0.0]
  We implement and investigate two methods of quantum circuit preparation for multiconfigurational states for quantum chemical applications.<n>We implement a method to automatically find the external controls required for utilizing Givens rotations to prepare multiconfigurational states on a quantum circuit.<n>We demonstrate the benefits of these techniques in a range of applications, including the ground states of a strongly correlated molecule.
  arXiv  Detail & Related papers  (2025-08-07T13:40:59Z)
• Multiple-basis representation of quantum states [1.1999555634662633]
  We explore a new hybrid, efficient quantum-classical representation of quantum states, the multiple-basis representation. This representation consists of a linear combination of states that are sparse in some given and different bases, specified by quantum circuits. We find cases in which this representation can be used, namely approximation of ground states, simulation of deeper computations by specifying bases with shallow circuits, and a tomographical protocol to describe states as multiple-basis representations.
  arXiv  Detail & Related papers  (2024-11-05T13:57:57Z)
• Absolute dimensionality of quantum ensembles [41.94295877935867]
  The dimension of a quantum state is traditionally seen as the number of superposed distinguishable states in a given basis. We propose an absolute, i.e.basis-independent, notion of dimensionality for ensembles of quantum states.
  arXiv  Detail & Related papers  (2024-09-03T09:54:15Z)
• Optimal quantum state tomography with local informationally complete measurements [25.33379738135298]
  We study whether a general MPS/MPDO state can be recovered with bounded errors using only a number of state copies in the number of qubits. We provide a positive answer for a variety of common many-body quantum states, including typical short-range entangled states, random MPS/MPDO states, and thermal states of one-dimensional Hamiltonians.
  arXiv  Detail & Related papers  (2024-08-13T17:58:02Z)
• Non-unitary Coupled Cluster Enabled by Mid-circuit Measurements on Quantum Computers [37.69303106863453]
  We propose a state preparation method based on coupled cluster (CC) theory, which is a pillar of quantum chemistry on classical computers. Our approach leads to a reduction of the classical computation overhead, and the number of CNOT and T gates by 28% and 57% on average.
  arXiv  Detail & Related papers  (2024-06-17T14:10:10Z)
• Parallel Quantum Computing Simulations via Quantum Accelerator Platform Virtualization [44.99833362998488]
  We present a model for parallelizing simulation of quantum circuit executions. The model can take advantage of its backend-agnostic features, enabling parallel quantum circuit execution over any target backend.
  arXiv  Detail & Related papers  (2024-06-05T17:16:07Z)
• Second Law of Entanglement Manipulation with Entanglement Battery [41.94295877935867]
  A central question since the beginning of quantum information science is how two distant parties can convert one entangled state into another. It has been conjectured that entangled state transformations could be executed reversibly in an regime, mirroring the nature of Carnot cycles in classical thermodynamics. We investigate the concept of an entanglement battery, an auxiliary quantum system that facilitates quantum state transformations without a net loss of entanglement.
  arXiv  Detail & Related papers  (2024-05-17T07:55:04Z)
• Solving reaction dynamics with quantum computing algorithms [42.408991654684876]
  We study quantum algorithms for response functions, relevant for describing different reactions governed by linear response. We focus on nuclear-physics applications and consider a qubit-efficient mapping on the lattice, which can efficiently represent the large volumes required for realistic scattering simulations.
  arXiv  Detail & Related papers  (2024-03-30T00:21:46Z)
• Preparing general mixed quantum states on quantum computers [0.0]
  We present an algorithm tailored for the preparation of $d$-dimensional mixed quantum states using quantum information processors. We conduct tests utilizing both X and non-X mixed two-qubit states, as well as arbitrary random density spanning one, two, and three qubits.
  arXiv  Detail & Related papers  (2024-02-06T18:09:51Z)
• Estimating the Number of States via the Rodeo Algorithm for Quantum Computation [0.0]
  We show how the recently developed rodeo algorithm can be utilized to determine the number of states associated with all energy levels. We apply it to compute the number of states of the 1D transverse-field Ising model and, consequently, its specific heat.
  arXiv  Detail & Related papers  (2023-12-07T14:29:15Z)
• Calculating the many-body density of states on a digital quantum computer [58.720142291102135]
  We implement a quantum algorithm to perform an estimation of the density of states on a digital quantum computer. We use our algorithm to estimate the density of states of a non-integrable Hamiltonian on the Quantinuum H1-1 trapped ion chip for a controlled register of 18bits.
  arXiv  Detail & Related papers  (2023-03-23T17:46:28Z)
• Quantum state inference from coarse-grained descriptions: analysis and an application to quantum thermodynamics [101.18253437732933]
  We compare the Maximum Entropy Principle method, with the recently proposed Average Assignment Map method. Despite the fact that the assigned descriptions respect the measured constraints, the descriptions differ in scenarios that go beyond the traditional system-environment structure.
  arXiv  Detail & Related papers  (2022-05-16T19:42:24Z)
• Entanglement catalysis for quantum states and noisy channels [41.94295877935867]
  We investigate properties of entanglement and its role for quantum communication. For transformations between bipartite pure states, we prove the existence of a universal catalyst. We further develop methods to estimate the number of singlets which can be established via a noisy quantum channel.
  arXiv  Detail & Related papers  (2022-02-10T18:36:25Z)
• Quantum Causal Unravelling [44.356294905844834]
  We develop the first efficient method for unravelling the causal structure of the interactions in a multipartite quantum process. Our algorithms can be used to identify processes that can be characterized efficiently with the technique of quantum process tomography.
  arXiv  Detail & Related papers  (2021-09-27T16:28:06Z)
• All entangled states are quantum coherent with locally distinguishable bases [0.0]
  We find that a bipartite quantum state is entangled if and only if it is quantum coherent with respect to complete bases of states in the corresponding system distinguishable under local quantum operations and classical communication. The corresponding minimal quantum coherence is the entanglement of formation.
  arXiv  Detail & Related papers  (2020-08-25T16:28:50Z)
• Single-copies estimation of entanglement negativity [1.7179583883220435]
  Entanglement plays a central role in quantum information processing. We propose a scheme to estimate the entanglement negativity of any bi- partition of a composite system.
  arXiv  Detail & Related papers  (2020-04-23T17:57:01Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.