Scattering wave packets of hadrons in gauge theories: Preparation on a quantum computer
Zohreh Davoudi, Chung-Chun Hsieh, Saurabh V. Kadam
备注：
44 pages, 18 figures, 3 tables, v3: Version accepted to Quantum. Typos fixed, two new figures added, and minor structural changes to improve readability and address referees' suggestions
Quantum simulation holds promise of enabling a complete description of high-energy scattering processes rooted in gauge theories of the Standard Model. A first step in such simulations is preparation of interacting hadronic wave packets. To create the wave packets, one typically resorts to adiabatic evolution to bridge between wave packets in the free theory and those in the interacting theory, rendering the simulation resource intensive. In this work, we construct a wave-packet creation operator directly in the interacting theory to circumvent adiabatic evolution, taking advantage of resource-efficient schemes for ground-state preparation, such as variational quantum eigensolvers. By means of an ansatz for bound mesonic excitations in confining gauge theories, which is subsequently optimized using classical or quantum methods, we show that interacting mesonic wave packets can be created efficiently and accurately using digital quantum algorithms that we develop. Specifically, we obtain high-fidelity mesonic wave packets in the $Z_2$ and $U(1)$ lattice gauge theories coupled to fermionic matter in 1+1 dimensions. Our method is applicable to both perturbative and non-perturbative regimes of couplings. The wave-packet creation circuit for the case of the $Z_2$ lattice gauge theory is built and implemented on the Quantinuum H1-1 trapped-ion quantum computer using 13 qubits and up to 308 entangling gates. The fidelities agree well with classical benchmark calculations after employing a simple symmetry-based noise-mitigation technique. This work serves as a step toward quantum computing scattering processes in quantum chromodynamics.
Hadronic scattering in (1+1)D SU(2) lattice gauge theory from tensor networks
CERN（欧洲核子研究中心）；Universidad Nacional de Colombia（哥伦比亚国立大学）；University of California, Los Angeles（加州大学洛杉矶分校）；Central China Normal University（华中师范大学）；Universidade de Santiago de Compostela（圣地亚哥德孔波斯特拉大学）
Heralded Free-Electron Writing of the Most Subradiant State in an Atomic Array
School of Physics and Technology, Wuhan University（武汉大学物理科学与技术学院）；Department of Physics, Friedrich-Alexander University (FAU) Erlangen-Nürnberg（埃尔朗根-纽伦堡弗里德里希·亚历山大大学物理系）；Wuhan Institute of Quantum Technology（武汉量子技术研究院）
Analog quantum simulation of $ϕ^4$ field theory with a superconducting transmission line
Massachusetts Institute of Technology（麻省理工学院）；Research Laboratory of Electronics, Massachusetts Institute of Technology（麻省理工学院电子研究实验室）；Center for Theoretical Physics - a Leinweber Institute, Massachusetts Institute of Technology（麻省理工学院莱因韦伯理论物理中心）；Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology（麻省理工学院电气工程和计算机科学系）；Physics Division, Argonne National Laboratory（阿贡国家实验室物理部）；Air Force Research Laboratory, Information Directorate（空军研究实验室信息管理局）
