Universal Distribution of Topological Defects and Adiabatic Quantum Computation

报告题目: Universal Distribution of Topological Defects and Adiabatic Quantum Computation

报告人:Professor Adolfo del Campo (University of Basque Country, Spain)

报告时间:2019412日(周五) 下午1600-1700

报告地点:物理科技楼101

邀请人:徐震宇

报告摘要:When a quantum phase transition is crossed in finite time, critical slowing down leads to the breakdown of adiabatic dynamics and the formation of topological defects. The average density of defects scales with the quench rate following a universal power-law predicted by the Kibble-Zurek mechanism. We analyze the full counting statistics of kinks and report the exact kink number distribution in the transverse-field quantum Ising model. Kink statistics is described by the Poisson binomial distribution with all cumulants exhibiting a universal power-law scaling with the quench rate. In the absence of finite-size effects, the distribution approaches a normal one, a feature that is expected to apply broadly in systems described by the Kibble-Zurek mechanism. We shall discuss the implications of such universal signatures on the dynamics of quantum annealing and the performance of adiabatic quantum computers.

References:

1. Adolfo del Campo, Universal Statistics of Topological Defects Formed in a Quantum Phase Transition, Phys. Rev. Lett. 121, 200601 (2018).

2. Jin-Ming Cui, Fernando Javier Gómez-Ruiz, Yun-Feng Huang, Chuan-Feng Li, Guang-Can Guo, Adolfo del Campo, Testing quantum critical dynamics beyond the Kibble-Zurek mechanism with a trapped-ion simulator, arXiv:1903.02145.

3. Zhenyu Xu and Adolfo del Campo, Probing the full distribution of many-body observables by single-qubit interferometry, arXiv:1812.06983.

报告人简介:Professor Adolfo del Campo is an Ikerbasque Research Professor at the University of Basque Country and Donostia International Physics Center. He is best known for his work in quantum control and theoretical physics. He is notable as one of the co-pioneers of shortcuts to adiabaticity, quantum speed limits in open systems, time in quantum mechanics, and Kibble-Zurek mechanism. He was awarded a Distinguished J. Robert Oppenheimer Fellowship and Leon Heller prize in Theoretical Physics at Los Alamos National Laboratory.

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