Article
Quantum Science & Technology
Ilya N. Moskalenko, Ilya A. Simakov, Nikolay N. Abramov, Alexander A. Grigorev, Dmitry O. Moskalev, Anastasiya A. Pishchimova, Nikita S. Smirnov, Evgeniy Zikiy, Ilya A. Rodionov, Ilya S. Besedin
Summary: Researchers presented a two-qubit fluxonium-based quantum processor, demonstrating fSim-type and controlled-Z gates with fidelities of 99.55% and 99.23%, respectively, while suppressing residual ZZ interaction to the few kHz levels. High-fidelity single-qubit gates and ground state initialization were achieved using a galvanically coupled flux control line.
NPJ QUANTUM INFORMATION
(2022)
Article
Multidisciplinary Sciences
T. M. Graham, Y. Song, J. Scott, C. Poole, L. Phuttitarn, K. Jooya, P. Eichler, X. Jiang, A. Marra, B. Grinkemeyer, M. Kwon, M. Ebert, J. Cherek, M. T. Lichtman, M. Gillette, J. Gilbert, D. Bowman, T. Ballance, C. Campbell, E. D. Dahl, O. Crawford, N. S. Blunt, B. Rogers, T. Noel, M. Saffman
Summary: Gate-model quantum computers promise to solve computational problems by utilizing neutral-atom hyperfine qubits and strong entangling interactions provided by Rydberg states. Several quantum algorithms have been successfully demonstrated on a programmable neutral-atom quantum computer.
Article
Physics, Multidisciplinary
T. H. Chang, T. N. Wang, H. H. Jen, Y-C Chen
Summary: In this study, we successfully achieve a high-fidelity Rydberg CZ gate by optimizing the pulses in a neutral atom system. These optimized pulses are robust to experimental fluctuations and allow for fast gate operations under adjustable parameters, surpassing the traditional adiabatic operation regime.
NEW JOURNAL OF PHYSICS
(2023)
Article
Quantum Science & Technology
G. Pelegri, A. J. Daley, J. D. Pritchard
Summary: The study proposes a protocol for implementing high-fidelity multiqubit controlled phase gates on neutral atom qubits. The results show that high-fidelity quantum gates can be achieved in a relatively short time period using this protocol. This has potential implications and applications for future developments.
QUANTUM SCIENCE AND TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Jiandong Bai, Yang Liu, Shaofeng Fan, Shuo Liu, Wenyuan Liu, Qi Jie, Yijun Li, Junmin Wang
Summary: By studying the magic-wavelength optical dipole trap (ODT) for pre-cooled atoms, the differential light shift between two atomic states can be eliminated, resulting in the same transition frequency as atoms in free space. This has great significance for improving experimental repetition rate and reducing atomic decoherence in cold atom physics, quantum optics, and precision measurement. In this study, we calculate the dynamic polarizabilities of cesium 6S ground state and 7P excited state using the multi-level model for ODT, with laser wavelength ranging from 1200 to 2000 nm. The magic wavelengths for linearly and circularly polarized laser beams at the intersection of the dynamic polarizabilities of the two atomic states are obtained. Furthermore, we analyze the robustness of the magic trapping conditions and the feasibility of experimental operation near the telecom C-band wavelength.
RESULTS IN PHYSICS
(2023)
Article
Optics
Jiandong Bai, Xin Wang, Xiaokai Hou, Wenyuan Liu, Junmin Wang
Summary: The magic conditions of the Rydberg transition in cesium atoms were studied by calculating the dynamic polarizabilities, determining the magic angle and detuning. The magic optical dipole trap can confine ground-state and Rydberg-state atoms, achieving cancellation of differential light shift.
Article
Physics, Multidisciplinary
Pengfei Yang, Gang Li, Zhihui Wang, Pengfei Zhang, Tiancai Zhang
Summary: The fidelity and coherence time of gate operations on neutral atoms trapped in an optical dipole trap are crucial for their applications. The motion of the trapped atoms, considered as a classical oscillator in previous analyses, is now treated as a quantum oscillator. The influence of the atom's motion on gate fidelity and decoherence is studied by analyzing the population on its vibrational states. It is discovered that the fidelity of a coherent rotation gate is significantly limited by the temperature of the trapped atom. However, the dephasing between hyperfine states caused by the thermal motion of the atom can naturally rephase under certain stable conditions. Additionally, the decoherence due to fluctuations of the trap laser intensity is discussed. Cooling the atom into vibrational ground states and/or using a blue-detuned trap can greatly enhance both gate fidelity and coherence time. Furthermore, a "magic" trapping condition is proposed by preparing the atom into specific vibrational states.
NEW JOURNAL OF PHYSICS
(2022)
Article
Physics, Applied
Mingyu Kang, Ye Wang, Chao Fang, Bichen Zhang, Omid Khosravani, Jungsang Kim, Kenneth R. Brown
Summary: This study develops filter functions for Molmer-Sorensen gates in trapped-ion quantum computers, accurately predicting the change in gate error due to small parameter fluctuations at any frequency. Experimental results show that using these filter functions can significantly improve gate fidelity in a five-ion chain.
PHYSICAL REVIEW APPLIED
(2023)
Article
Chemistry, Physical
Gediminas J. Pazera, Matthew D. Krzyaniak, Michael R. Wasielewski
Summary: This theoretical study investigates pulse sequence protocols for spin-correlated radical pairs, which are important molecular spin qubit pair (SQP) candidates. The study demonstrates that the proposed pulse sequences effectively remove certain contributions from nuclear spin effects on spin dynamics and analyzes the factors that control the fidelity of the SQP spin state.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Physics, Multidisciplinary
Meng Li, Jing-Yang Li, Fu-Qiang Guo, Xiao-Yu Zhu, Erjun Liang, Shou Zhang, Lei-Lei Yan, Mang Feng, Shi-Lei Su
Summary: This paper proposes a scheme to directly construct multiple-qubit logic gates, which can greatly reduce the number of qubits and operation steps, improving the speed and robustness of the gates. The scheme is based on Rydberg blockade, geometric quantum operations, and optimized control theory. The performance of the proposed scheme is numerically evaluated on the C2U2 gate.
ANNALEN DER PHYSIK
(2022)
Article
Optics
Guosheng Feng, Zhixing Qiao, Tao Yin, Jizhou Wu, Hui Zhang
Summary: We conducted a comprehensive study on the optimized loading of ultracold Cs atoms in a magnetic levitated crossed dipole trap. The effects of the dipole laser's opening time and power intensity on the loading efficiency were analyzed. Experimental measurements showed that the number of atoms can be significantly increased through the pre-loading process.
Article
Physics, Multidisciplinary
Kavish Bhardwaj, S. P. Ram, S. Singh, V. B. Tiwari, S. R. Mishra
Summary: This work investigates the effect of AC-Stark shift of atomic energy levels in an optical dipole trap on in situ absorption imaging of trapped atoms. The estimated number of atoms trapped in the ODT is found to be higher at higher ODT beam power, showing qualitative agreement with larger trap depth at higher beam power. This research can be particularly useful in estimating the in situ loss rate of atoms from the trap during evaporative cooling of the trapped atom cloud.
Article
Computer Science, Hardware & Architecture
Yongshang Li, Yu Zhang, Mingyu Chen, Xiangyang Li, Peng Xu
Summary: Neutral atoms (NAs) have potential advantages in quantum computing, but require compilation to overcome long-range interactions. We propose an abstract mechanism and heuristic algorithm to optimize the execution time of quantum circuits on neutral atom quantum computers.
IEEE TRANSACTIONS ON COMPUTER-AIDED DESIGN OF INTEGRATED CIRCUITS AND SYSTEMS
(2023)
Article
Optics
Wenliang Liu, Ningxuan Zheng, Xiaofeng Wang, Jing Xu, Yuqing Li, Vladimir B. Sovkov, Peng Li, Yongming Fu, Jizhou Wu, Jie Ma, Liantuan Xiao, Suotang Jia
Summary: The experiment presents a method for quickly producing Bose-Einstein condensates (BECs) of Na-23 atoms, creating a pure F = 1 BEC of approximately 1.1 x 10^5 sodium atoms with a fast forced evaporation process. The system reliably generates the condensate at a rate exceeding 10^5 atoms every approximately 8 seconds. Additionally, the lifetimes of the mixed F = 1 condensate and the spin components (m ( F ) = 0, m ( F ) = +1) were compared.
JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS
(2021)
Article
Engineering, Electrical & Electronic
I. I. Beterov, E. A. Yakshina, D. B. Tretyakov, V. M. Entin, N. Al'yanova, K. Yu Mityanin, A. M. Faruk, I. I. Ryabtsev
Summary: This experiment successfully implemented individually addressable one-qubit quantum gates on two Rb-87 atoms. Rabi oscillations with high frequency, contrast, and coherence time were obtained without addressing. Addressing effectively suppressed the probability of microwave transitions in the addressed atom.
QUANTUM ELECTRONICS
(2021)
Article
Optics
Yong Zeng, Zhuo Fu, Yang-Yang Liu, Xiao-Dong He, Min Liu, Peng Xu, Xiao-Hong Sun, Jin Wang
Summary: In this study, a method of optical phase modulation in the PDH technique was developed using an AOM for stable phase and light power coupling. The laser linewidth was suppressed to approximately 907.91 Hz using this method.
Article
Physics, Multidisciplinary
Yang-Yang Liu, Zhuo Fu, Peng Xu, Xiao-Dong He, Jin Wang, Ming-Sheng Zhan
Summary: An alternative method for spectral filtering and frequency stabilization of 780-nm and 960-nm lasers using a high-finesse length-tunable cavity (HFLTC) is proposed and demonstrated. The obtained lasers show ultra-low phase noise and narrow linewidth, which are essential for high precision atomic experiments.
Article
Physics, Applied
Yangyang Liu, Yuan Sun, Zhuo Fu, Peng Xu, Xin Wang, Xiaodong He, Jin Wang, Mingsheng Zhan
Summary: This study investigates the coherence of ground-Rydberg transitions in a single atom subjected to various pulse sequences, particularly focusing on the CZ gate sequence. It is found that the process experienced by the control qubit atom under a two-qubit entangling process with the H-CZ controlled-NOT gate scheme is essentially similar to ground-Rydberg Ramsey interference. A theoretical model linking the decoherence time of the control qubit to the CZ pulse sequence is established, shedding light on the origins of decoherence effects and potential ways to improve fidelity of the CZ gate.
PHYSICAL REVIEW APPLIED
(2021)
Article
Multidisciplinary Sciences
Cheng Sheng, Zheng Ling, Yicong Luo, Wanbin Zhang
Summary: N,O-acetals are important building blocks for many synthetic intermediates, natural products, and pharmaceutical drugs. The authors developed a Cu-catalyzed asymmetric addition of alcohols to beta,gamma-alkynyl-alpha-imino esters, providing linear chiral N,O-ketals with high enantioselectivity.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Cheng Sheng, Zheng Ling, Tanveer Ahmad, Fang Xie, Wanbin Zhang
Summary: This study achieved the regioselective [3+3] annulation of alkynyl ketimines with alpha-cyano ketones using Cu(OAc)(2) as the catalyst, resulting in the synthesis of polysubstituted 4H-pyran derivatives with a quaternary CF3-containing center. The strategy demonstrated excellent tolerance towards a wide range of alpha-CF3 alkynyl ketimines and alpha-cyano ketones with various aryl and alkyl substituents. Moreover, asymmetric synthesis of chiral product 3 was attempted and yielded high yields and enantioselectivities. The research has significant implications in the synthesis of polysubstituted 4H-pyran derivatives.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Physics, Multidisciplinary
Cheng Sheng, Jiayi Hou, Xiaodong He, Kunpeng Wang, Ruijun Guo, Jun Zhuang, Bahtiyar Mamat, Peng Xu, Min Liu, Jin Wang, Mingsheng Zhan
Summary: This study reports the first demonstration of two-dimensional dual-species atom assembly, achieved by rearranging initially randomly distributed atoms using a sorting algorithm and optical trapping technique. The resulting atom arrays have user-defined geometries and specific species ratios, making them highly attractive for applications in high-fidelity quantum logic, many-body quantum simulation, and single molecule array formation.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Zhi-Jin Tao, Li-Geng Yu, Peng Xu, Jia-Yi Hou, Xiao-Dong He, Ming-Sheng Zhan
Summary: Dual-species single-atom array in optical tweezers is a preferable choice for quantum computing and quantum simulation. However, creating a defect-free array with a large number of atoms is challenging. We propose a heuristic connectivity optimization algorithm that rearranges the stochastically loaded dual-species atoms into desired configurations with the near-fewest number of atom moves. Tested in various array sizes and configurations, our algorithm demonstrates high success rate, low extra atom moves, scalability, and flexibility.
CHINESE PHYSICS LETTERS
(2022)
Editorial Material
Optics
Peng Xu, Ming-Sheng Zhan
Summary: The energy exchange between two Rydberg atoms has been induced and observed on a nanosecond timescale, which paves the way for the realization of ultrafast quantum gates.
Article
Computer Science, Hardware & Architecture
Yongshang Li, Yu Zhang, Mingyu Chen, Xiangyang Li, Peng Xu
Summary: Neutral atoms (NAs) have potential advantages in quantum computing, but require compilation to overcome long-range interactions. We propose an abstract mechanism and heuristic algorithm to optimize the execution time of quantum circuits on neutral atom quantum computers.
IEEE TRANSACTIONS ON COMPUTER-AIDED DESIGN OF INTEGRATED CIRCUITS AND SYSTEMS
(2023)
Article
Optics
Zhuo Fu, Peng Xu, Yuan Sun, Yang-Yang Liu, Xiao-Dong He, Xiao Li, Min Liu, Run-Bing Li, Jin Wang, Liang Liu, Ming-Sheng Zhan
Summary: This article reports experimental results on the realization of a two-qubit controlled-PHASE (CZ) gate via single-modulated-pulse off-resonant modulated driving in rubidium (Rb) atoms. The gate operation is completed using a carefully calculated smooth waveform global driving laser pulse and combined with global microwave pulses to generate two-atom entanglement.
