Protecting Quantum State in Time‐Dependent Decoherence‐Free Subspaces Without the Rotating‐Wave Approximation

Wu, Qi‐Cheng; Chen, Ye‐Hong; Huang, Bi‐Hua; Shi, Zhi‐Cheng; Song, Jie; Xia, Yan

doi:10.1002/andp.201700186

Cited by 10 publications

(3 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This requires considerable extra resources to reach the fault-tolerant threshold. Besides, some particular QIP tasks are well designed in the decoherence-free subspace [56,57] to avoid entanglement loss. The difficulty is finding the decoherence-free subspace and the feasibility of information coding in such space.…”

Section: Introductionmentioning

confidence: 99%

Quantum Entanglement Protection by Utilizing Classical Noises

Zheng,

Huang,

Zhao

et al. 2023

Adv Quantum Tech

Self Cite

View full text Add to dashboard Cite

Noise is often considered as the biggest enemy of maintaining quantum entanglement. However, in this paper, it shows quantum entanglement can be protected by introducing extra noises to a quantum system. As an example, the dynamics of a two‐qubit system coupled to a cavity is studied under the influence of three noises, a quantized noise from the leakage of the cavity and two classical noises in the couplings between the two‐qubit system and the cavity. The master equation beyond the Markov approximation is derived and the mechanism of the entanglement protection is analyzed in a special case with analytical solutions. In short, the entanglement loss caused by the dissipation to the bath might be weaken by introducing high‐frequency classical noises properly. The numerical simulations not only confirm the feasibility of protecting entanglement by noises but also reveal that the properties of the classical noises have a significant impact on the performance of the entanglement protection.

show abstract

Section: Introductionmentioning

confidence: 99%

Quantum Entanglement Protection by Utilizing Classical Noises

Zheng,

Huang,

Zhao

et al. 2023

Adv Quantum Tech

Self Cite

View full text Add to dashboard Cite

show abstract

“…The rotating wave approximation (RWA) [12] being successfully exploited for various LWI studies can become unjustified for highly off-resonant schemes. In references [13][14][15][16] it was shown that going beyond the RWA results in new features which cannot be obtained within the RWA. Another example is provided in reference [17] studying the Rabi splitting phenomenon in a quantum well system where the RWA breaks down and the counter-rotating wave terms play a significant role in the system dynamics.…”

Section: Introductionmentioning

confidence: 99%

Highly non-resonant lasing without inversion gain in a ladder scheme

Braunstein¹,

Koganov²,

Smolik³

et al. 2020

J. Phys. B: At. Mol. Opt. Phys.

View full text Add to dashboard Cite

We show that it is possible to get gain without inversion at high frequency in a three-level ladder type scheme driven by a single driving laser. The transition from the ground state to first excited state is driven by a low-frequency resonant laser field. The next excited state lies far above the first one; therefore its resonant frequency can be much higher than that of the lower transition, and hence one should go beyond the most commonly used rotating wave approximation consisting of retaining only resonant terms (slowly oscillating) in the Hamiltonian. We solve the master equation, both analytically (under proper approximations) and numerically, with the full Hamiltonian keeping counter-rotating highly non-resonant terms. We show a dressed state picture explaining spectral features of gain-absorption profiles. Also we present a kind of phase diagram in the plane γ–Λ, where γ and Λ are spontaneous emission rate and incoherent pumping rate, respectively. The whole γ–Λ plane is divided into four areas: gain-inversion, absorption-no inversion, gain without inversion and absorption with inversion. The first two are usual regimes of incoherently pumped lasers, while the last two stem from the quantum interference phenomena. We analyse the parameter areas where such quantum regimes are possible. The exact numerical solution of the time-dependent master equation shows that keeping counter-rotating terms (no rotating wave approximation) gives rise to new spectral features in the form of additional peaks at combination frequencies. Actually the considered system works as a coherent frequency up-converter.

show abstract

“…Moreover, one can manipulate atoms with classical fields readily . In recent year, the development of the technique of shortcuts in adiabaticity (STA), have greatly promoted pulse design for fast and robust control of atoms in cavity QED systems. Combining the advances of cavity QED systems and STA, many protocols have been put forward to realize the preparations of atomic entangled states, which have all shown strong power of STA.…”

Section: Introductionmentioning

confidence: 99%

Robust Preparation of Atomic Concatenated Greenberger–Horne–Zeilinger States via Shortcuts to Adiabaticity

Lin

2018

Annalen der Physik

View full text Add to dashboard Cite

Here, a protocol for robust preparation of an atomic concatenated Greenberger-Horne-Zeilinger (C-GHZ) state via shortcuts to adiabaticity (STA) is proposed. The devices for implementing the protocol consist of atoms, cavities, and the optical fibers, which are feasible with current technology. The atoms are trapped in the separated cavities allowing individual control over each atom with classical fields. STA helps to design Rabi frequencies of classical fields so that the atoms can be driven from the initial states to the target states. The numerical simulations show that the protocol holds robustness against atomic spontaneous emissions and photonic leakages. Thus, the protocol may be realized by experiments in the near future.been proposed to prepare the GHZ states with different systems. For example, Zheng [21] has proposed a protocol to generate GHZ states with atoms. Wu et al. [23] have used the superconducting qubits to generate GHZ states.The protocols [21][22][23] for preparing the GHZ states mentioned above focus on the GHZ states encoded in the physical qubits directly. Recently, Fröwis and Dür [24,25] have suggested a new type of entangled states named concatenated Greenberger-Horne-Zeilinger (C-GHZ) states, which are the GHZ-like states encoded in the qubits formed by the traditional GHZ states. More specifically, the C-GHZ states can be written as DenotationState of system Denotation State of system |ψ 1 | 0, 0, 0, 0 |0 | ψ 2 | 0, 2, 0, 0 |0 |ψ 3 | 0, 1, 0, 0 |1 11l | ψ 4 | 0, 1, 0, 0 |1 f 11 |ψ 5 | 0, 1, 0, 0 |1 0l | ψ 6 | 0, 1, 1, 1 |0 |ψ 7 | 1, 0, 0, 0 |0 | ψ 8 | 1, 1, 0, 0 |0 |ψ 9 | 1, 1, 0, 0 |1 11l | ψ 10 | 1, 2, 0, 0 |1 f 11 |ψ 11 | 1, 1, 0, 0 |1 0l | ψ 12 | 2, 0, 0, 0 |0 |ψ 13 | 3, 1, 0, 0 |0

show abstract

Protecting Quantum State in Time‐Dependent Decoherence‐Free Subspaces Without the Rotating‐Wave Approximation

Cited by 10 publications

References 60 publications

Quantum Entanglement Protection by Utilizing Classical Noises

Quantum Entanglement Protection by Utilizing Classical Noises

Highly non-resonant lasing without inversion gain in a ladder scheme

Robust Preparation of Atomic Concatenated Greenberger–Horne–Zeilinger States via Shortcuts to Adiabaticity

Contact Info

Product

Resources

About