Accidental Symmetry in the Tavis-Cummings Model via the Schwinger Boson Representation

• URL: http://arxiv.org/abs/2606.12813v1
• Date: Thu, 11 Jun 2026 02:13:51 GMT
• Title: Accidental Symmetry in the Tavis-Cummings Model via the Schwinger Boson Representation
• Abstract summary: In the multi-qubit setting, where n qubits are identically coupled to a single boson mode, this interaction is known as the Tavis-Cummings (TC) Hamiltonian.<n>We identify an additional, independent "accidental" symmetry of the TC Hamiltonian and construct the corresponding conserved observable.<n>These restrictions have important implications for controllability of the TC system and for its applications to quantum computing.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: The Jaynes-Cummings (JC) Hamiltonian is a paradigmatic model of light-matter interaction and, more generally, qubit-boson interactions, widely used across atomic, optical, and superconducting qubit platforms. In the multi-qubit setting, where n qubits are identically coupled to a single boson mode, this interaction is known as the Tavis-Cummings (TC) Hamiltonian. The structure of the TC model is usually understood in terms of two standard symmetries: permutation invariance of the qubits and a U(1) symmetry associated with conservation of the total excitation number. Here we identify an additional, independent "accidental" symmetry of the TC Hamiltonian and construct the corresponding conserved observable. We show that, for n>2 qubits, this symmetry imposes strong constraints on the realizable unitary transformations. These constraints persist in the presence of the global $J_z$ Hamiltonian, but are removed by adding $J_z^2$, even though $J_z^2$ preserves both permutation invariance and the U(1) symmetry. Finally, we explain the origin of this previously unnoticed symmetry using Schwinger's boson representation of angular momentum. These restrictions have important implications for controllability of the TC system and for its applications to quantum computing, which are investigated further in a companion paper.

Related papers

• Entangling Power and Symmetries in the Quantum Rabi Model [0.0]
  We show that the time-averaged entangling power responds to both the hidden symmetry and the $U(1)$ symmetry in the Rabi family.<n>Results demonstrate that the entangling power can serve as an operator diagnostic to reveal the presence and properties of hidden and manifest symmetries in light-matter systems.
  arXiv  Detail & Related papers  (2026-07-13T18:11:55Z)
• Global Control with the Tavis-Cummings Interaction [0.0]
  We study the controllability of a system of qubits under global control, where control pulses act identically on all qubits.<n>We characterize the group of unitaries that can be implemented on the joint Hilbert space of the qubits and bosonic mode.<n>We show that for n>2 qubits the set of realizable unitaries is restricted by an "accidental" symmetry of the TC Hamiltonian.
  arXiv  Detail & Related papers  (2026-06-11T05:03:47Z)
• $\mathcal{PT}$-like phase transitions from square roots of supersymmetric Hamiltonians [0.0]
  We introduce a general framework for realizing $mathcalPT$-like phase transitions in non-Hermitian systems.<n>This work uncovers new links between non-Hermitian physics and supersymmetry.
  arXiv  Detail & Related papers  (2025-11-16T23:38:51Z)
• Kubo-Martin-Schwinger relation for energy eigenstates of SU(2)-symmetric quantum many-body systems [41.94295877935867]
  We show that non-Abelian symmetries may alter conventional thermodynamics.<n>This work helps extend into nonequilibrium physics the effort to identify how non-Abelian symmetries may alter conventional thermodynamics.
  arXiv  Detail & Related papers  (2025-07-09T19:46:47Z)
• Meson spectroscopy of exotic symmetries of Ising criticality in Rydberg atom arrays [39.58317527488534]
  Coupling two Ising chains in a ladder leads to an even richer $mathcalD(1)_8$ symmetries.<n>Here, we probe these emergent symmetries in a Rydberg atom processing unit, leveraging its geometry to realize both chain and ladder configurations.
  arXiv  Detail & Related papers  (2025-06-26T14:19:30Z)
• Symmetry-deformed toric codes and the quantum dimer model [0.24578723416255746]
  We investigate symmetry-based deformations of topological order by systematically deconstructing the Gauss-law-enforcing star terms of the toric code (TC) Hamiltonian.<n>This "term-dropping" protocol introduces global symmetries that go beyond the alternative framework of "ungauging" topological order in symmetry-deformed models.
  arXiv  Detail & Related papers  (2025-05-30T18:00:01Z)
• Symmetries, Conservation Laws and Entanglement in Non-Hermitian Fermionic Lattices [37.69303106863453]
  Non-Hermitian quantum many-body systems feature steady-state entanglement transitions driven by unitary dynamics and dissipation.<n>We show that the steady state is obtained by filling single-particle right eigenstates with the largest imaginary part of the eigenvalue.<n>We illustrate these principles in the Hatano-Nelson model with periodic boundary conditions and the non-Hermitian Su-Schrieffer-Heeger model.
  arXiv  Detail & Related papers  (2025-04-11T14:06:05Z)
• Controlling Symmetries and Quantum Criticality in the Anisotropic Coupled-Top Model [32.553027955412986]
  We investigate the anisotropic coupled-top model, which describes the interactions between two large spins along both $x-$ and $y-$directions.<n>We can manipulate the system's symmetry, inducing either discrete $Z$ or continuous U(1) symmetry.<n>The framework provides an ideal platform for experimentally controlling symmetries and investigating associated physical phenomena.
  arXiv  Detail & Related papers  (2025-02-13T15:14:29Z)
• Predicting symmetries of quantum dynamics with optimal samples [41.42817348756889]
  Identifying symmetries in quantum dynamics is a crucial challenge with profound implications for quantum technologies.<n>We introduce a unified framework combining group representation theory and subgroup hypothesis testing to predict these symmetries with optimal efficiency.<n>We prove that parallel strategies achieve the same performance as adaptive or indefinite-causal-order protocols.
  arXiv  Detail & Related papers  (2025-02-03T15:57:50Z)
• Symmetry-restricted quantum circuits are still well-behaved [45.89137831674385]
  We show that quantum circuits restricted by a symmetry inherit the properties of the whole special unitary group $SU(2n)$. It extends prior work on symmetric states to the operators and shows that the operator space follows the same structure as the state space.
  arXiv  Detail & Related papers  (2024-02-26T06:23:39Z)
• Dark-state solution and symmetries of the two-qubit multimode asymmetric quantum Rabi model [6.510240597572375]
  We study the two-qubit asymmetric quantum Rabi model (AQRM) and find its dark-state solution. We find symmetries related with conserved bosonic number operators, which also cause level crossings.
  arXiv  Detail & Related papers  (2023-10-31T22:33:28Z)
• Quantum Current and Holographic Categorical Symmetry [62.07387569558919]
  A quantum current is defined as symmetric operators that can transport symmetry charges over an arbitrary long distance. The condition for quantum currents to be superconducting is also specified, which corresponds to condensation of anyons in one higher dimension.
  arXiv  Detail & Related papers  (2023-05-22T11:00:25Z)
• Symmetry from Entanglement Suppression [0.0]
  We show that a minimally entangling $S$-matrix would give rise to global symmetries. For $N_q$ species of qubit, the Identity gate is associated with an $[SU(2)]N_q$ symmetry.
  arXiv  Detail & Related papers  (2021-04-22T02:50:10Z)

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.