Helicity-dependent ultrafast spin current generated by circularly polarized photons in topological materials holds the crux to many technological improvements,such as quantum communications,on-chip communication proce...Helicity-dependent ultrafast spin current generated by circularly polarized photons in topological materials holds the crux to many technological improvements,such as quantum communications,on-chip communication processing and storage.Here,we present the manipulation of helicity-dependent terahertz emission generated in a nodal line semimetal candidate Mg3Bi2 by using photon polarization states.The terahertz emission is mainly ascribed to the helicity-dependent photocurrent that is originated from circular photogalvanic effects,and the helicity-independent photocurrent that is attributed to linear photogalvanic effect.Our work will inspire more explorations into novel nodal line semimetals and open up new opportunities for developing ultrafast optoelectronics in the topological system.展开更多
Activation of silent synapses is of great significance for the extension of neural plasticity related to learning and memory.Inspired by the activation of silent synapses via receptor insertion in neural synapses,we p...Activation of silent synapses is of great significance for the extension of neural plasticity related to learning and memory.Inspired by the activation of silent synapses via receptor insertion in neural synapses,we propose an efficient method for activating artificial synapses through the intercalation of Sn in layered a-MoO_(3).Sn intercalation is capable of switching on the response of layered a-MoO_(3)to the stimuli of visible and near infrared light by decreasing the bandgap.This mimics the receptor insertion process in silent neural synapses.The Sn-intercalated MoO_(3)(Sn-MoO_(3))exhibits persistent photoconductivity due to the donor impurity induced by Sn intercalation.This enables the two-terminal Sn-MoO_(3)device promising optoelectronic synapse with an ultrahigh paired pulse facilitation(PPF)up to 199.5%.On-demand activation and tunable synaptic plasticity endow the device great potentials for extensible neuromorphic computing.Superior performance of the extensible artificial neural network(ANN)based on the Sn-MoO_(3)synapses are demonstrated in pattern recognition.Impressively,the recognition accuracy increases from 89.7%to 94.8%by activating more nodes into the ANN.This is consistent with the recognition process of physical neural network during brain development.The intercalation engineering of MoO_(3)may provide inspirations for the design of high-performance neuromorphic computing architectures.展开更多
基金We thank Prof.J.B.Qi for helpful discussions and are grateful for financial support from the National Natural Science Foundation of China(Grant Nos.11804387,11802339,11805276,11902358,61805282,and 61801498)the Scientific Researches Foundation of National University of Defense Technology(Grant Nos.ZK18-03-22,ZK18-01-03 and ZK18-03-36).
文摘Helicity-dependent ultrafast spin current generated by circularly polarized photons in topological materials holds the crux to many technological improvements,such as quantum communications,on-chip communication processing and storage.Here,we present the manipulation of helicity-dependent terahertz emission generated in a nodal line semimetal candidate Mg3Bi2 by using photon polarization states.The terahertz emission is mainly ascribed to the helicity-dependent photocurrent that is originated from circular photogalvanic effects,and the helicity-independent photocurrent that is attributed to linear photogalvanic effect.Our work will inspire more explorations into novel nodal line semimetals and open up new opportunities for developing ultrafast optoelectronics in the topological system.
基金National Natural Science Foundation of China(52103311,62075240)the Scientific Researches Foundation of National University of Defense Technology(ZK18-01-03)National Key Research and Development Program of China(2020YFB2205804).
文摘Activation of silent synapses is of great significance for the extension of neural plasticity related to learning and memory.Inspired by the activation of silent synapses via receptor insertion in neural synapses,we propose an efficient method for activating artificial synapses through the intercalation of Sn in layered a-MoO_(3).Sn intercalation is capable of switching on the response of layered a-MoO_(3)to the stimuli of visible and near infrared light by decreasing the bandgap.This mimics the receptor insertion process in silent neural synapses.The Sn-intercalated MoO_(3)(Sn-MoO_(3))exhibits persistent photoconductivity due to the donor impurity induced by Sn intercalation.This enables the two-terminal Sn-MoO_(3)device promising optoelectronic synapse with an ultrahigh paired pulse facilitation(PPF)up to 199.5%.On-demand activation and tunable synaptic plasticity endow the device great potentials for extensible neuromorphic computing.Superior performance of the extensible artificial neural network(ANN)based on the Sn-MoO_(3)synapses are demonstrated in pattern recognition.Impressively,the recognition accuracy increases from 89.7%to 94.8%by activating more nodes into the ANN.This is consistent with the recognition process of physical neural network during brain development.The intercalation engineering of MoO_(3)may provide inspirations for the design of high-performance neuromorphic computing architectures.
