# Quantum Zeno effects across a parity-time symmetry breaking transition in atomic momentum space

@article{Chen2020QuantumZE, title={Quantum Zeno effects across a parity-time symmetry breaking transition in atomic momentum space}, author={Tao Chen and Wei Gou and Dizhou Xie and Teng Xiao and Wei Yi and Jun Jing and Bo Yan}, journal={npj Quantum Information}, year={2020}, volume={7}, pages={1-6} }

We experimentally study quantum Zeno effects in a parity-time (PT) symmetric cold atom gas periodically coupled to a reservoir. Based on the state-of-the-art control of inter-site couplings of atoms in a momentum lattice, we implement a synthetic two-level system with passive PT symmetry over two lattice sites, where an effective dissipation is introduced through repeated couplings to the rest of the lattice. Quantum Zeno (anti-Zeno) effects manifest in our experiment as the overall dissipation…

## 11 Citations

### Decoherence-Induced Exceptional Points in a Dissipative Superconducting Qubit.

- PhysicsPhysical review letters
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Open quantum systems interacting with an environment exhibit dynamics described by the combination of dissipation and coherent Hamiltonian evolution. Taken together, these effects are captured by a…

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- 2021

Parity-time ($\mathcal{PT}$)-symmetric systems, featuring real eigenvalues despite their non-Hermitian nature, undergo spontaneous $\mathcal{PT}$ symmetry breaking at the exceptional point (EP). The…

### Quantum Zeno repeaters

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- PhysicsJournal of Physics: Conference Series
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Quantum information processing relies on the precise control of non-classical states in the presence of many uncontrolled environmental degrees of freedom. The interactions between the relevant…

## References

SHOWING 1-10 OF 73 REFERENCES

### Passive parity-time-symmetry-breaking transitions without exceptional points in dissipative photonic systems [Invited]

- PhysicsPhotonics Research
- 2018

Over the past decade, parity-time (PT)-symmetric Hamiltonians have been experimentally realized in classical, optical settings with balanced gain and loss, or in quantum systems with localized loss.…

### Observation of parity-time symmetry breaking in a single-spin system

- PhysicsScience
- 2019

It is shown that non-Hermitian physics can be found in a solid-state quantum system through a protocol, termed dilation, which transformed a PT-symmetric Hamiltonian into a Hermitian one, and the quantum state evolutions ranging from regions of unbroken to broken PT symmetry have been observed with a single nitrogen-vacancy center in diamond.

### Topological Quantum Walks in Momentum Space with a Bose-Einstein Condensate.

- PhysicsPhysical review letters
- 2020

The experimental implementation of discrete-time topological quantum walks of a Bose-Einstein condensate in momentum space is reported, which directly measures the underlying topological invariants through time-averaged mean chiral displacements, which is consistent with the experimental observation of topological phase transitions.

### Suppressing the loss of ultracold molecules via the continuous quantum Zeno effect.

- PhysicsPhysical review letters
- 2014

This work quantitatively explains the recently observed suppression of chemical reactions between two rotational states of fermionic KRb molecules confined in one-dimensional tubes with a weak lattice along the tubes.

### Quantum state tomography across the exceptional point in a single dissipative qubit

- PhysicsNature Physics
- 2019

Open systems with gain and loss, described by non-trace-preserving, non-Hermitian Hamiltonians, have been a subject of intense research recently. The effect of exceptional-point degeneracies on the…

### Experimental realization of quantum zeno dynamics

- PhysicsNature communications
- 2014

This work harnesses measurements and strong couplings to dynamically disconnect different groups of quantum states and constrain the atoms to coherently evolve inside a two-level subregion in a five-level Hilbert space.

### Tunable Nonreciprocal Quantum Transport through a Dissipative Aharonov-Bohm Ring in Ultracold Atoms.

- PhysicsPhysical review letters
- 2020

The experimental observation of tunable, nonreciprocal quantum transport of a Bose-Einstein condensate in a momentum lattice by implementing a dissipative Aharonov-Bohm ring in momentum space and demonstrating a directional atom flow is reported.

### Deterministic generation of multiparticle entanglement by quantum Zeno dynamics

- PhysicsScience
- 2015

This work used quantum Zeno dynamics (QZD), based on nondestructive measurement with an optical microcavity, to deterministically generate different multiparticle entangled states in an ensemble of 36 qubit atoms in less than 5 microseconds, yielding a time-resolved account of the entanglement generation.

### Engineering tunable local loss in a synthetic lattice of momentum states

- PhysicsNew Journal of Physics
- 2019

Dissipation can serve as a powerful resource for controlling the behavior of open quantum systems. Recently there has been a surge of interest in the influence of dissipative coupling on large…

### Dissipation-facilitated molecules in a Fermi gas with non-Hermitian spin-orbit coupling

- Physics, Chemistry
- 2019

We study the impact of non-Hermiticity on the molecule formation in a two-component spin-orbit-coupled Fermi gas near a wide Feshbach resonance. Under an experimentally feasible configuration where…