Minutes-scale Schr{ö}dinger-cat state of spin-5/2 atoms

Abstract

Quantum metrology with nonclassical states offers a promising route to improved precision in physical measurements. The quantum effects of Schr{ö}dinger-cat superpositions or entanglements allow measurement uncertainties to reach below the standard quantum limit. However, the challenge in keeping a long coherence time for such nonclassical states often prevents full exploitation of the quantum advantage in metrology. Here we demonstrate a long-lived Schr{ö}dinger-cat state of optically trapped ${}^{173}$Yb (\textit{I}\ =\ 5/2) atoms. The cat state, a superposition of two oppositely-directed and furthest-apart spin states, is generated by a non-linear spin rotation. Protected in a decoherence-free subspace against inhomogeneous light shifts of an optical lattice, the cat state achieves a coherence time of $1.4(1)\times 10^3$ s. A magnetic field is measured with Ramsey interferometry, demonstrating a scheme of Heisenberg-limited metrology for atomic magnetometry, quantum information processing, and searching for new physics beyond the Standard Model.

References in corpus (33)

• Decoherence, einselection, and the quantum origins of the classical
• Decoherence Free Subspaces for Quantum Computation
• Quantum metrology with nonclassical states of atomic ensembles
• Search for New Physics with Atoms and Molecules
• Nonlinear atom interferometer surpasses classical precision limit
• Super-resolving phase measurements with a multi-photon entangled state
• Advances in High Dimensional Quantum Entanglement
• Reconstruction of non-classical cavity field states with snapshots of their decoherence
• De Broglie Wavelength of a Nonlocal Four-Photon
• Electric Dipole Moments of the Atoms, Molecules, Nuclei and Particles
• Fisher Information and entanglement of non-Gaussian spin states
• Quantum State Engineering and Precision Metrology using State-Insensitive Light Traps
• A universal qudit quantum processor with trapped ions
• 'Designer atoms' for quantum metrology
• Single ion-qubit exceeding one hour coherence time
• Entanglement-Enhanced Optical Atomic Clock
• Single-qubit quantum memory exceeding $10$-minute coherence time
• Macroscopic quantum states: measures, fragility and implementations
• Entanglement with Negative Wigner Function of Three Thousand Atoms Heralded by One Photon
• Dynamical polarizability of atoms in arbitrary light fields: general theory and application to cesium
• Schrödinger cat states of a 16-microgram mechanical oscillator
• Measurements with prediction and retrodiction on the collective spin of 10^{11} atoms beat the standard quantum limit
• Nonclassicality as a Quantifiable Resource for Quantum Metrology
• Entanglement-Enhanced Matter-Wave Interferometry in a High-Finesse Cavity
• Continuous Weak Measurement and Nonlinear Dynamics in a Cold Spin Ensemble
• Anisotropic Polarizability of Ultracold Polar ${}^{40}$K${}^{87}$Rb Molecules
• Quantum-enhanced sensing using non-classical spin states of a highly magnetic atom
• AC Stark shift of the Cs microwave atomic clock transitions
• Nonlinear interferometry beyond classical limit facilitated by cyclic dynamics
• Ultra-low noise magnetic field for quantum gases
• Tomographic reconstruction of the Wigner function on the Bloch sphere
• Measurement of the Electric Dipole Moment of ${}^{171}$Yb Atoms in an Optical Dipole Trap
• Magic Wavelengths of the Yb $6s^2{}^1{S}_0-6s6p{}^3{P}_1$ Intercombination Transition

Cited by in corpus (9)

• Microscopic theory of a precessing ferromagnet for ultrasensitive magnetometry
• Enhancing Dynamic Range of Sub-Quantum-Limit Measurements via Quantum Deamplification
• Dark spin-cats as biased qubits
• Cold-atom comagnetometry via optical control of spin states
• Single photonic qutrit in a collective Rydberg polariton
• Deterministic nuclear spin squeezing and squeezing by continuous measurement using vector and tensor light shifts
• Fault-Tolerant Encoding of Logical Qudits in Spin Systems
• Universality in fidelity-based quantum metrology
• Reservoir-Engineered Mechanical Cat States with a Driven Qubit