劉雄軍 教授；北京大學(xué)
題目：Quantum simulation for Rydberg atoms with laser-assisted dipole-dipole interactions
時間：2023年5月13日 下午 14:00
地點：惟真樓2樓219
摘要：Rydberg
atoms with dipole-dipole interactions and arranged in arrays provide
intriguing platforms to explore exotic quantum many-body physics. In
this talk, following a pedagogic introduction to the Rydberg atoms, I
will present a novel mechanism that we proposed recently, dubbed
laser-assisted dipole-dipole interactions, to realize synthetic gauge
fields and correlated topological states for Rydberg atom arrays. In the
presence of an energy offset between neighboring Rydberg atoms, the
bare dipole-dipole interaction between them is suppressed, but an
effective dipole-dipole interaction can be assisted when Raman lights
are applied to compensate the energy difference. With this scheme we are
able to simulate various novel correlated quantum matters. In
particular, we first achieve a feasible scheme to generate tunable
synthetic gauge fields for the complex spin-exchange coupling model,
which realizes the highly tunable flat Chern bands of the hard core
bosons are obtained and further, the bosonic fractional quantum Hall
states. Moreover, the laser-assisted dipole-dipole interaction can be
broadly applied to various Rydberg atom array configurations,
particularly the Raman superarrays of Rydberg atoms. In the Rydberg
superarray of 1D ladder configuration, we show an exactly solvable model
which hosts the exotic quantum critical states. In the 2D case, we
propose a novel stripe lattice model to realize a fractional quantum
anomalous Hall phase, with the manipulation and detection via correlated
quench dynamics being introduced and discussed.
劉雄軍教授2011年于德州A&M大學(xué)獲博士學(xué)位。之后分別在馬里蘭大學(xué)，香港科大高等研究院及麻省理工學(xué)院從事博士后研究。他2014年9月加入北大量子材料中心任研究員，入選國家人才項目。2018年7月獲長聘，同年8月獲得國家杰青資助，2019年1月晉升正教授、北大博雅特聘教授。劉雄軍長期在拓撲超導(dǎo)等拓撲物相和超冷原子量子模擬領(lǐng)域開展研究，取得一系列原創(chuàng)和引領(lǐng)性成果，獲得2019年亞太物理學(xué)會和亞太理論物理中心“楊振寧獎（CN
Yang Award）”等榮譽。發(fā)迄今表論文80余篇，包括Science, Science子刊，Nature Physics, PRL,
PRX等權(quán)威期刊40余篇。
李有泉 教授；南開大學(xué)
題目：Manipulation of Skyrmions and the Promising Applications
時間：2023年5月13日 下午 14:00
地點：新綜合樓2樓219
摘要：There
has been spectacular progress in the study on multiferroics, which is
expected to make a realistic step toward an electrical control of
magnetism or four state memories. We propose a tilted Heisenberg model
of which the continuum limit is a gauge Landau-Lifshitz equation that
provides a unified description for various exotic spin orders appeared.
For certain gauge potential, we solved the magnetic skyrmion phase and
also predicted the emergence of meron phase. We also propose a mechanism
to pin skyrmions in chiral magnet, and find that the position-dependent
electric field can induce the Hall motion of the skyrmion. Furthermore,
we study spin-orbital driven ferroelectricity; spin-orbital coupling
and charge effect in Mott insulators showing that the tilted Heisenberg
model can be derived from the Hubbard model in the presence of
spin-orbital coupling as the large U limit. The idea of tilted
Heisenberg model has been extended to the SU(3) case by experts working
on high-energy physics recently. Moreover, we show that in the
stationary regime the chirality of the domain wall can be efficiently
reversed when the electric field is applied along the direction of the
magnetic field. These characteristics suggest that the multiferroic
domain wall may provide a new prospective means to design faster and
low-power-consumption domain wall devices. These results are expected to
motivate experimentalists to prepare new type of multiferroics material
or design new spintronics device.
李有泉，教授、博導(dǎo)，長期從事理論凝聚態(tài)物理研究工作，發(fā)表論文160余篇；主持國家自然科學(xué)基金13項、國家重點研發(fā)計劃項目1項；獲國家自然科學(xué)二等獎1項、中國高校自然科學(xué)一等獎1項；入選“教育部長江學(xué)者”，“新世紀(jì)百千萬人才工程”國家級人選“國家萬人計劃”--百千萬工程領(lǐng)軍人才；獲全國“五一”勞動獎?wù)隆⒘魧W(xué)回國人員成就獎?wù)录暗诎藢弥袊嗄昕萍吉劊辉巍犊茖W(xué)通報》、《Frontiers
of Physics》、《物理學(xué)進展》等期刊編委，現(xiàn)任中國物理學(xué)會秋季會議、全國磁學(xué)理論會議等組委會委員。
