Spin-projection for quantum computation: A low-depth approach to strong correlation

• URL: http://arxiv.org/abs/2004.12024v2
• Date: Mon, 21 Dec 2020 01:25:41 GMT
• Title: Spin-projection for quantum computation: A low-depth approach to strong correlation
• Authors: Takashi Tsuchimochi and Yuto Mori and Seiichiro L. Ten-no
• Abstract summary: We will demonstrate that the broken spin-symmetry can be restored exactly in a quantum computer, with little overhead in circuits. The proposed scheme permits drastic reduction of a potentially large number of measurements required to ensure spin-symmetry.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Although spin is a core property in fermionic systems, its symmetry can be easily violated in a variational simulation, especially when strong correlation plays a vital role therein. In this study, we will demonstrate that the broken spin-symmetry can be restored exactly in a quantum computer, with little overhead in circuits, while delivering additional strong correlation energy with the desired spin quantum number. The proposed scheme permits drastic reduction of a potentially large number of measurements required to ensure spin-symmetry by employing a superposition of only a few rotated quantum states. Our implementation is universal, simple, and, most importantly, straightforwardly applicable to any ansatz proposed to date.

Related papers

• Quantum channel for modeling spin-motion dephasing in Rydberg chains [44.99833362998488]
  We introduce a quantum channel to model the dissipative dynamics resulting from the coupling between spin and motional degrees of freedom in chains of neutral atoms with Rydberg interactions.<n>We benchmark the accuracy of our approach against exact diagonalization for small systems, identifying its regime of validity and the onset of perturbative breakdown.<n>We then apply the quantum channel to compute fidelity loss during transport of single-spin excitations across extended Rydberg chains in intractable regimes via exact diagonalization.
  arXiv  Detail & Related papers  (2025-06-30T17:37:38Z)
• Harnessing Chiral Spin States in Molecular Nanomagnets for Quantum Technologies [44.1973928137492]
  We show that chiral qubits naturally suppress always-on interactions that can not be switched off in weakly coupled qubits. Our findings establish spin chirality engineering as a promising strategy for mitigating always-on interaction in entangling two chiral qubits in molecular quantum technologies.
  arXiv  Detail & Related papers  (2025-01-21T08:23:12Z)
• Quantum computing in spin-adapted representations for efficient simulations of spin systems [0.0]
  We introduce a novel formalism for designing quantum algorithms directly in an eigenbasis of the total-spin operator. We show that this formalism yields a hierarchy of spin-adapted Hamiltonians, for each truncation threshold. These truncated Hamiltonians can be encoded with sparse and local qubit Hamiltonians that are suitable for quantum simulations.
  arXiv  Detail & Related papers  (2024-12-19T12:38:20Z)
• Powering a quantum clock with a non-equilibrium steady state [50.24983453990065]
  We propose powering a quantum clock with the non-thermal resources offered by the stationary state of an integrable quantum spin chain. Using experimentally relevant examples of quantum spin chains, we suggest crossing a phase transition point is crucial for optimal performance.
  arXiv  Detail & Related papers  (2024-12-17T17:25:11Z)
• Precision bounds for multiple currents in open quantum systems [37.69303106863453]
  We derivation quantum TURs and KURs for multiple observables in open quantum systems undergoing Markovian dynamics. Our bounds are tighter than previously derived quantum TURs and KURs for single observables. We also find an intriguing quantum signature of correlations captured by the off-diagonal element of the Fisher information matrix.
  arXiv  Detail & Related papers  (2024-11-13T23:38:24Z)
• Spin Squeezing with Magnetic Dipoles [37.93140485169168]
  Entanglement can improve the measurement precision of quantum sensors beyond the shot noise limit. We take advantage of the magnetic dipole-dipole interaction native to most neutral atoms to realize spin-squeezed states. We achieve 7.1 dB of metrologically useful squeezing using the finite-range spin exchange interactions in an erbium quantum gas microscope.
  arXiv  Detail & Related papers  (2024-11-11T18:42:13Z)
• Oscillatory dissipative tunneling in an asymmetric double-well potential [32.65699367892846]
  Chemical research will benefit from a fully controllable, asymmetric double-well equipped with precise measurement capabilities of the tunneling rates. Our work paves the way for analog molecule simulators based on quantum superconducting circuits.
  arXiv  Detail & Related papers  (2024-09-19T22:43:07Z)
• Scalable spin squeezing in two-dimensional arrays of dipolar large-$S$ spins [0.0]
  We show that spin-spin interactions lead to scalable spin squeezing along the non-equilibrium unitary evolution in a coherent spin state. For sufficiently small quadratic shifts, the spin squeezing dynamics is akin to that produced by the paradigmatic one-axis-twisting (OAT) model. Spin squeezing with OAT-like scaling is shown to be protected by the robustness of long-range ferromagnetic order to quadratic shifts.
  arXiv  Detail & Related papers  (2023-09-11T10:32:24Z)
• Entanglement and replica symmetry breaking in a driven-dissipative quantum spin glass [17.92148801290204]
  We describe a quantum cavity QED system that realizes an intrinsically driven-dissipative spin glass. We observe that entanglement plays an important role in the emergence of replica symmetry breaking. This practicable system could serve as a testbed for exploring how quantum effects enrich the physics of spin glasses.
  arXiv  Detail & Related papers  (2023-07-19T17:59:14Z)
• Control of an environmental spin defect beyond the coherence limit of a central spin [79.16635054977068]
  We present a scalable approach to increase the size of electronic-spin registers. We experimentally realize this approach to demonstrate the detection and coherent control of an unknown electronic spin outside the coherence limit of a central NV. Our work paves the way for engineering larger quantum spin registers with the potential to advance nanoscale sensing, enable correlated noise spectroscopy for error correction, and facilitate the realization of spin-chain quantum wires for quantum communication.
  arXiv  Detail & Related papers  (2023-06-29T17:55:16Z)
• Universality of critical dynamics with finite entanglement [68.8204255655161]
  We study how low-energy dynamics of quantum systems near criticality are modified by finite entanglement. Our result establishes the precise role played by entanglement in time-dependent critical phenomena.
  arXiv  Detail & Related papers  (2023-01-23T19:23:54Z)
• Quantum and classical correlations in open quantum-spin lattices via truncated-cumulant trajectories [0.0]
  We show a new method to treat open quantum-spin lattices, based on the solution of the open-system dynamics. We validate this approach in the paradigmatic case of the phase transitions of the dissipative 2D XYZ lattice, subject to spontaneous decay.
  arXiv  Detail & Related papers  (2022-09-27T13:23:38Z)
• Symmetric Pruning in Quantum Neural Networks [111.438286016951]
  Quantum neural networks (QNNs) exert the power of modern quantum machines. QNNs with handcraft symmetric ansatzes generally experience better trainability than those with asymmetric ansatzes. We propose the effective quantum neural tangent kernel (EQNTK) to quantify the convergence of QNNs towards the global optima.
  arXiv  Detail & Related papers  (2022-08-30T08:17:55Z)
• Importance Sampling Scheme for the Stochastic Simulation of Quantum Spin Dynamics [0.0]
  We develop an importance sampling scheme for the simulation of quantum spin dynamics. An exact transformation is then carried out to preferentially sample trajectories that are close to the dominant one. We demonstrate that this approach is capable of reducing the temporal growth of fluctuations in the quantities.
  arXiv  Detail & Related papers  (2021-03-30T16:18:28Z)
• Dynamical replica analysis of quantum annealing [0.0]
  An interesting alternative approach to the dynamics of quantum spin systems was proposed about a decade ago. It involves creating a proxy dynamics via the Suzuki-Trotter mapping of the quantum ensemble to a classical one. In this chapter we give an introduction to this approach, focusing on the ideas and assumptions behind the derivations.
  arXiv  Detail & Related papers  (2020-10-23T12:17:38Z)

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.