Imaginary-time-enhanced feedback-based quantum algorithms for universal ground-state preparation

• URL: http://arxiv.org/abs/2512.13044v1
• Date: Mon, 15 Dec 2025 07:12:03 GMT
• Title: Imaginary-time-enhanced feedback-based quantum algorithms for universal ground-state preparation
• Authors: Thanh Nguyen Van Long, Lan Nguyen Tran, Le Bin Ho,
• Abstract summary: We introduce an imaginary-time-enhanced FALQON scheme, which inserts short imaginary-time evolution steps into the feedback loop.<n>The hybrid method suppresses excited-state components, escapes subspaces, and restores monotonic energy descent.<n>ITE-FALQON achieves a reliable ground-state convergence across all fillings.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Preparing ground states of strongly correlated quantum systems is a central goal in quantum simulation and optimization. The feedback-based quantum algorithm (FALQON) provides an attractive alternative to variational methods with a fully quantum feedback rule, but it fails in the presence of spectral degeneracies, where the feedback signal collapses and the evolution cannot reach the ground state. Using the Fermi-Hubbard model on lattices up to 3x3, we show that this breakdown appears at half-filling on the 2x2 lattice and extends to both half-filled and doped configurations on the 3x3 lattice. We then introduce an imaginary-time-enhanced FALQON (ITE-FALQON) scheme, which inserts short imaginary-time evolution steps into the feedback loop. The hybrid method suppresses excited-state components, escapes degenerate subspaces, and restores monotonic energy descent. The ITE-FALQON achieves a reliable ground-state convergence across all fillings, providing a practical route to scalable ground-state preparation in strongly correlated quantum systems.

Related papers

• Robust population transfer by a detuning sign jump: from two-state quantum system to SU(2)-symmetric three-state quantum system [0.0]
  We analyze a robust population-transfer protocol in a driven two-level system based on a sudden sign change of the detuning.<n>We show that for strong coupling the protocol yields almost complete population transfer between the two outer states.
  arXiv  Detail & Related papers  (2025-12-11T08:40:33Z)
• Universal quantum control by non-Hermitian Hamiltonian [0.42970700836450487]
  We control a finite-dimensional quantum system under a time-dependent non-Hermitian Hamiltonian.<n>Our protocol is explicitly verified for the perfect population transfer in the two-level system and the chiral population transfer in the three-level system.
  arXiv  Detail & Related papers  (2025-05-24T09:00:20Z)
• Cost of Locally Approximating High-Dimensional Ground States of Contextual Quantum Models [1.5844265436419382]
  Contextuality, one of the strongest forms of quantum correlations, delineates the quantum world and the classical one.<n>Some quantum models, in the form of infinite one-dimensional translation-invariant Hamiltonians, have the lowest ground state energy density allowed in quantum physics.<n>We develop a universal set of permutation-symmetry preserving qubit-based gates, using them as an ansatz to simulate parameterized quantum circuits designed for qutrits.
  arXiv  Detail & Related papers  (2024-05-08T08:35:31Z)
• Measurement-Induced Transmon Ionization [69.65384453064829]
  We develop a comprehensive framework which provides a physical picture of the origin of transmon ionization. This framework identifies the multiphoton resonances responsible for transmon ionization. It also allows one to efficiently compute numerical estimates of the photon number threshold for ionization.
  arXiv  Detail & Related papers  (2024-02-09T18:46:50Z)
• From Heisenberg to Hubbard: An initial state for the shallow quantum simulation of correlated electrons [0.0]
  We propose a three-step deterministic quantum routine to prepare an educated guess of the ground state of the Fermi-Hubbard model. First, the ground state of the Heisenberg model is suitable for near-term quantum hardware. Second, a general method is devised to convert a multi-spin-$frac12$ wave function into its fermionic version.
  arXiv  Detail & Related papers  (2023-10-25T17:05:50Z)
• Dissipative preparation and stabilization of many-body quantum states in a superconducting qutrit array [55.41644538483948]
  We present and analyze a protocol for driven-dissipatively preparing and stabilizing a manifold of quantum manybody entangled states. We perform theoretical modeling of this platform via pulse-level simulations based on physical features of real devices. Our work shows the capacity of driven-dissipative superconducting cQED systems to host robust and self-corrected quantum manybody states.
  arXiv  Detail & Related papers  (2023-03-21T18:02:47Z)
• Non-Gaussian superradiant transition via three-body ultrastrong coupling [62.997667081978825]
  We introduce a class of quantum optical Hamiltonian characterized by three-body couplings. We propose a circuit-QED scheme based on state-of-the-art technology that implements the considered model.
  arXiv  Detail & Related papers  (2022-04-07T15:39:21Z)
• Determining ground-state phase diagrams on quantum computers via a generalized application of adiabatic state preparation [61.49303789929307]
  We use a local adiabatic ramp for state preparation to allow us to directly compute ground-state phase diagrams on a quantum computer via time evolution. We are able to calculate an accurate phase diagram on both two and three site systems using IBM quantum machines.
  arXiv  Detail & Related papers  (2021-12-08T23:59:33Z)
• Realization of arbitrary doubly-controlled quantum phase gates [62.997667081978825]
  We introduce a high-fidelity gate set inspired by a proposal for near-term quantum advantage in optimization problems. By orchestrating coherent, multi-level control over three transmon qutrits, we synthesize a family of deterministic, continuous-angle quantum phase gates acting in the natural three-qubit computational basis.
  arXiv  Detail & Related papers  (2021-08-03T17:49:09Z)
• State preparation and measurement in a quantum simulation of the O(3) sigma model [65.01359242860215]
  We show that fixed points of the non-linear O(3) sigma model can be reproduced near a quantum phase transition of a spin model with just two qubits per lattice site. We apply Trotter methods to obtain results for the complexity of adiabatic ground state preparation in both the weak-coupling and quantum-critical regimes. We present and analyze a quantum algorithm based on non-unitary randomized simulation methods.
  arXiv  Detail & Related papers  (2020-06-28T23:44:12Z)
• Roadmap for quantum simulation of the fractional quantum Hall effect [0.0]
  A major motivation for building a quantum computer is that it provides a tool to efficiently simulate strongly correlated quantum systems. In this work, we present a detailed roadmap on how to simulate a two-dimensional electron gas---cooled to absolute zero and pierced by a strong magnetic field---on a quantum computer.
  arXiv  Detail & Related papers  (2020-03-05T10:17:21Z)

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.