arXiv subjects

Qi-Cheng Wu

Publications and source records attributed to Qi-Cheng Wu.

22 records · Page 2Linked to original sources

arXiv2016

Method for constructing shortcuts to adiabaticity by a substitute of counterdiabatic driving terms

We propose an efficientmethod to construct shortcuts to adiabaticity through designing a substitute Hamiltonian to try to avoid the defect in which the speed-up protocol' Hamiltonian may involve terms which are difficult to realize in practice. We show that as long as the counterdiabatic coupling terms-even only some of them-have been nullified by the additional Hamiltonian, the corresponding shortcuts to the adiabatic process could be constructed and the adiabatic process would be sped up. As an application example, we apply this method to the popular Landau-Zener model for the realization of fast population inversion. The results show that in both Hermitian and non-Hermitian systems, we can design different additional Hamiltonians to replace the traditional counterdiabatic driving Hamiltonian to speed up the process. This method provides many choices for designing additional terms of the Hamiltonian such that one can choose a realizable model in practice.

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arXiv2014

Adiabatic passage for three-dimensional entanglement generation through quantum Zeno dynamics

We propose an adiabatic passage approach to generate two atoms three- dimensional entanglement with the help of quantum Zeno dynamics in a time- dependent interacting field. The atoms are trapped in two spatially separated cavi- ties connected by a fiber, so that the individual addressing is needless. Because the scheme is based on the resonant interaction, the time required to generate entangle- ment is greatly shortened. Since the fields remain in vacuum state and all the atoms are in the ground states, the losses due to the excitation of photons and the spon- taneous transition of atoms are suppressed efficiently compared with the dispersive protocols. Numerical simulation results show that the scheme is robust against the decoherences caused by the cavity decay and atomic spontaneous emission. Addi- tionally, the scheme can be generalized to generate N-atom three-dimensional en- tanglement and high-dimensional entanglement for two spatially separated atoms.

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arXiv2014

Generation of atomic NOON states via adiabatic passage

We propose a scheme for generating atomic NOON states via adiabatic passage. In the scheme, a double $Λ$-type three-level atom is trapped in a bimodal cavity and two sets of $Λ$-type three-level atoms are translated into and outside of two single mode cavities respectively. The three cavities connected by optical fibres are always in vacuum states. After a series of operations and suitable interaction time, we can obtain arbitrary large-$n$ NOON states of two sets of $Λ$-type three-level atoms in distant cavities by performing a single projective measurement on the double $Λ$-type three-level atom. Due to adiabatic elimination of atomic excited states and the application of adiabatic passage, our scheme is robust against the spontaneous emissions of atoms, the decays of fibres and cavities photon leakage. So the scheme has a high fidelity and feasibility under the current available techniques.

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arXiv2014

Preparation of Knill-Lafamme-Milburn states based on superconducting qutrits

We propose two schemes for generating the Knill-Lafamme-Milburn (KLM) states of two distant polar molecules (PMs) ensembles respectively in two transmission-line resonators (TLRs) connected by a superconducting charge qutrit (SCQ), and of two SCQs in a TLR, respectively. Both of the schemes are robust against photon decay due to the virtual excitations of the microwave photons of the TLRs, and the spontaneous emission can be suppressed owing to the virtual transitions of the SCQs in the second scheme. In addition, the schemes have high controllability and feasibility under the current available techniques.

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