Harnessing the enhanced light-matter coupling and quantum vacuum fluctuations resulting from mode volume compression in optical cavities is a promising route towards functionalizing quantum materials and realizing exo...Harnessing the enhanced light-matter coupling and quantum vacuum fluctuations resulting from mode volume compression in optical cavities is a promising route towards functionalizing quantum materials and realizing exotic states of matter.Here,we extend cavity quantum electrodynamical materials engineering to correlated magnetic systems,by demonstrating that a Fabry-Pérot cavity can be used to control the magnetic state of the proximate quantum spin liquidα-RuCl_(3).Depending on specific cavity properties such as the mode frequency,photon occupation,and strength of the light-matter coupling,any of the magnetic phases supported by the extended Kitaev model can be stabilized.In particular,in the THz regime,we show that the cavity vacuum fluctuations alone are sufficient to bringα-RuCl_(3) from a zigzag antiferromagnetic to a ferromagnetic state.By external pumping of the cavity in the few photon limit,it is further possible to push the system into the antiferromagnetic Kitaev quantum spin liquid state.展开更多
Magnetic skyrmions are topological excitations of great promise for compact and efficient memory storage.However,to interface skyrmionics with electronic devices requires efficient and reliable ways of creating and de...Magnetic skyrmions are topological excitations of great promise for compact and efficient memory storage.However,to interface skyrmionics with electronic devices requires efficient and reliable ways of creating and destroying such excitations.In this work,we unravel the microscopic mechanism behind ultrafast skyrmion generation by femtosecond laser pulses in transition metal thin films.We employ a theoretical approach based on a two-band electronic model,and show that by exciting the itinerant electronic subsystem with a femtosecond laser ultrafast skyrmion nucleation can occur on a 100 fs timescale.By combining numerical simulations with an analytical treatment of the strong s–d exchange limit,we identify the coupling between electronic currents and the localized d-orbital spins,mediated via Rashba spin–orbit interactions among the itinerant electrons,as the microscopic and central mechanism leading to ultrafast skyrmion generation.Our results show that an explicit treatment of itinerant electron dynamics is crucial to understand optical skyrmion generation.展开更多
基金We acknowledge support by the Max Planck Institute New York City Center for Non-Equilibrium Quantum Phenomena,the Cluster of Excellence‘CUI:Advanced Imaging of Matter’-EXC 2056-project ID 390715994 and SFB-925“Light induced dynamics and control of correlated quantum systems”-project 170620586 of the Deutsche Forschungsgemeinschaft(DFG),and Grupos Consolidados(IT1453-22).E.V.B.acknowledges funding from the European Union’s Horizon Europe research and innovation program under the Marie Skłodowska-Curie grant agreement No.101106809.The Flatiron Institute is a Division of the Simons Foundation.
文摘Harnessing the enhanced light-matter coupling and quantum vacuum fluctuations resulting from mode volume compression in optical cavities is a promising route towards functionalizing quantum materials and realizing exotic states of matter.Here,we extend cavity quantum electrodynamical materials engineering to correlated magnetic systems,by demonstrating that a Fabry-Pérot cavity can be used to control the magnetic state of the proximate quantum spin liquidα-RuCl_(3).Depending on specific cavity properties such as the mode frequency,photon occupation,and strength of the light-matter coupling,any of the magnetic phases supported by the extended Kitaev model can be stabilized.In particular,in the THz regime,we show that the cavity vacuum fluctuations alone are sufficient to bringα-RuCl_(3) from a zigzag antiferromagnetic to a ferromagnetic state.By external pumping of the cavity in the few photon limit,it is further possible to push the system into the antiferromagnetic Kitaev quantum spin liquid state.
基金We acknowledge support by the Max Planck Institute New York City Center for Non-Equilibrium Quantum Phenomena and by the Swedish Research Council.We also acknowledge support from the European Research Council(ERC-2015-AdG694097)the Cluster of Excellence“Advanced Imaging of Matter”(AIM),and Grupos Consolidados(IT1249-19).
文摘Magnetic skyrmions are topological excitations of great promise for compact and efficient memory storage.However,to interface skyrmionics with electronic devices requires efficient and reliable ways of creating and destroying such excitations.In this work,we unravel the microscopic mechanism behind ultrafast skyrmion generation by femtosecond laser pulses in transition metal thin films.We employ a theoretical approach based on a two-band electronic model,and show that by exciting the itinerant electronic subsystem with a femtosecond laser ultrafast skyrmion nucleation can occur on a 100 fs timescale.By combining numerical simulations with an analytical treatment of the strong s–d exchange limit,we identify the coupling between electronic currents and the localized d-orbital spins,mediated via Rashba spin–orbit interactions among the itinerant electrons,as the microscopic and central mechanism leading to ultrafast skyrmion generation.Our results show that an explicit treatment of itinerant electron dynamics is crucial to understand optical skyrmion generation.
