Building blocks of quantum computers have been demonstrated in small to intermediate-scale systems.As one of the leading platforms,the trapped ion system has attracted wide attention.A significant challenge in this sy...Building blocks of quantum computers have been demonstrated in small to intermediate-scale systems.As one of the leading platforms,the trapped ion system has attracted wide attention.A significant challenge in this system is to combine fast high-fidelity gates with scalability and convenience in ion trap fabrication.Here we propose an architecture for large-scale quantum computing with a two-dimensional array of atomic ions trapped at such large distance which is convenient for ion-trap fabrication but usually believed to be unsuitable for quantum computing as the conventional gates would be too slow.Using gate operations far outside of the Lamb–Dicke region,we show that fast and robust entangling gates can be realized in any large ion arrays.The gate operations are intrinsically parallel and robust to thermal noise,which,together with their high speed and scalability of the proposed architecture,makes this approach an attractive one for large-scale quantum computing.展开更多
Dissipation is often considered as a detrimental effect in quantum systems for unitary quantum operations.However,it has been shown that suitable dissipation can be useful resources in both quantum information and qua...Dissipation is often considered as a detrimental effect in quantum systems for unitary quantum operations.However,it has been shown that suitable dissipation can be useful resources in both quantum information and quantum simulation.Here,we propose and experimentally simulate a dissipative phase transition(DPT)model using a single trapped ion with an engineered reservoir.We show that the ion’s spatial oscillation mode reaches a steady state after the alternating application of unitary evolution under a quantum Rabi model Hamiltonian and sideband cooling of the oscillator.The average phonon number of the oscillation mode is used as the order parameter to provide evidence for the DPT.Our work highlights the suitability of trapped ions for simulating open quantum systems and shall facilitate further investigations of DPT with various dissipation terms.展开更多
High fidelity single shot qubit state readout is essential for many quantum information processing protocols. In superconducting quantum circuit, the qubit state is usually determined by detecting the dispersive frequ...High fidelity single shot qubit state readout is essential for many quantum information processing protocols. In superconducting quantum circuit, the qubit state is usually determined by detecting the dispersive frequency shift of a microwave cavity from either transmission or reflection. We demonstrate the use of constructive interference between the transmitted and reflected signal to optimize the qubit state readout, with which we find a better resolved state discrimination and an improved qubit readout fidelity. As a simple and convenient approach, our scheme can be combined with other qubit readout methods based on the discrimination of cavity photon states to further improve the qubit state readout.展开更多
基金supported by the National key Research and Development Program of China(Grant No.2016YFA0301902)the Frontier Science Center for Quantum Information of the Ministry of Education of China,and the Tsinghua University Initiative Scientific Research Programsupport from Shuimu Tsinghua Scholar Program and the International Postdoctoral Exchange Fellowship Program。
文摘Building blocks of quantum computers have been demonstrated in small to intermediate-scale systems.As one of the leading platforms,the trapped ion system has attracted wide attention.A significant challenge in this system is to combine fast high-fidelity gates with scalability and convenience in ion trap fabrication.Here we propose an architecture for large-scale quantum computing with a two-dimensional array of atomic ions trapped at such large distance which is convenient for ion-trap fabrication but usually believed to be unsuitable for quantum computing as the conventional gates would be too slow.Using gate operations far outside of the Lamb–Dicke region,we show that fast and robust entangling gates can be realized in any large ion arrays.The gate operations are intrinsically parallel and robust to thermal noise,which,together with their high speed and scalability of the proposed architecture,makes this approach an attractive one for large-scale quantum computing.
基金supported by the Beijing Academy of Quantum Information Sciencesthe National Key Research and Development Program of China(Grant No.2016YFA0301902)+2 种基金Frontier Science Center for Quantum Information of the Ministry of Education of ChinaTsinghua University Initiative Scientific Research Programsupport from Shuimu Tsinghua Scholar Program and International Postdoctoral Exchange Fellowship Program(Talent-Introduction Program)。
文摘Dissipation is often considered as a detrimental effect in quantum systems for unitary quantum operations.However,it has been shown that suitable dissipation can be useful resources in both quantum information and quantum simulation.Here,we propose and experimentally simulate a dissipative phase transition(DPT)model using a single trapped ion with an engineered reservoir.We show that the ion’s spatial oscillation mode reaches a steady state after the alternating application of unitary evolution under a quantum Rabi model Hamiltonian and sideband cooling of the oscillator.The average phonon number of the oscillation mode is used as the order parameter to provide evidence for the DPT.Our work highlights the suitability of trapped ions for simulating open quantum systems and shall facilitate further investigations of DPT with various dissipation terms.
基金Supported by the Beijing Academy of Quantum Information Sciencethe Frontier Science Center for Quantum Information of the Ministry of Education of China through the Tsinghua University Initiative Scientific Research Program+3 种基金the National Natural Science Foundation of China (Grant No. 11874235)the National Key Research and Development Program of China (Grant Nos. 2016YFA0301902 and 2020YFA0309500)support from Shuimu Tsinghua Scholar Programthe International Postdoctoral Exchange Fellowship Program。
文摘High fidelity single shot qubit state readout is essential for many quantum information processing protocols. In superconducting quantum circuit, the qubit state is usually determined by detecting the dispersive frequency shift of a microwave cavity from either transmission or reflection. We demonstrate the use of constructive interference between the transmitted and reflected signal to optimize the qubit state readout, with which we find a better resolved state discrimination and an improved qubit readout fidelity. As a simple and convenient approach, our scheme can be combined with other qubit readout methods based on the discrimination of cavity photon states to further improve the qubit state readout.
