Using the determinant quantum Monte Carlo method,we explore a rich phase diagram featuring strain-induced metal-insulator and magnetic phase transitions in an interacting two-dimensional Dirac fermion system.Asymmetri...Using the determinant quantum Monte Carlo method,we explore a rich phase diagram featuring strain-induced metal-insulator and magnetic phase transitions in an interacting two-dimensional Dirac fermion system.Asymmetric strain applied along the zigzag crystal direction drives the semimetallic regime into a band-insulating phase,or it breaks the antiferromagnetic order of the Mott insulator,inducing a nonmagnetic insulating phase under strong correlations.The critical strain required for band gap opening or for a transport phase transition is significantly reduced in the presence of Coulomb repulsion,while increasing interaction strength makes it more difficult for strain to induce a nonmagnetic phase transition.In addition,we measure in detail the band gap modulation by strain and identify a doping effect whereby doping inhibits band gap opening.Our results provide an effective way to tune the transport gap,which could help extend the applications of graphene,whose zero band gap currently limits its use.展开更多
The proliferation of the global datasphere has forced cloud storage systems to evolve more complex architectures for different applications.The emergence of these application session requests and system daemon service...The proliferation of the global datasphere has forced cloud storage systems to evolve more complex architectures for different applications.The emergence of these application session requests and system daemon services has created large persistent flows with diverse performance requirements that need to coexist with other types of traffic.Current routing methods such as equal-cost multipath(ECMP)and Hedera do not take into consideration specific traffic characteristics nor performance requirements,which make these methods difficult to meet the quality of service(QoS)for high-priority flows.In this paper,we tailored the best routing for different kinds of cloud storage flows as an integer programming problem and utilized grey relational analysis(GRA)to solve this optimization problem.The resulting method is a GRAbased service-aware flow scheduling(GRSA)framework that considers requested flow types and network status to select appropriate routing paths for flows in cloud storage datacenter networks.The results from experiments carried out on a real traffic trace show that the proposed GRSA method can better balance traffic loads,conserve table space and reduce the average transmission delay for high-priority flows compared to ECMP and Hedera.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.12474218)the Beijing Natural Science Foundation(Grant No.1242022)the Guangxi Key Laboratory of Precision Navigation Technology and Application,Guilin University of Electronic Technology(Grant No.DH202322)。
文摘Using the determinant quantum Monte Carlo method,we explore a rich phase diagram featuring strain-induced metal-insulator and magnetic phase transitions in an interacting two-dimensional Dirac fermion system.Asymmetric strain applied along the zigzag crystal direction drives the semimetallic regime into a band-insulating phase,or it breaks the antiferromagnetic order of the Mott insulator,inducing a nonmagnetic insulating phase under strong correlations.The critical strain required for band gap opening or for a transport phase transition is significantly reduced in the presence of Coulomb repulsion,while increasing interaction strength makes it more difficult for strain to induce a nonmagnetic phase transition.In addition,we measure in detail the band gap modulation by strain and identify a doping effect whereby doping inhibits band gap opening.Our results provide an effective way to tune the transport gap,which could help extend the applications of graphene,whose zero band gap currently limits its use.
基金supported by National Natural Science Foundation of China(Nos.61861013,61662018)Science and Technology Major Project of Guangxi(No.AA18118031)+2 种基金Guangxi Natural Science Foundation of China(No.2018 GXNSFAA050028)the Doctoral Research Foundation of Guilin University of Electronic Science and Technology(No.UF19033Y)Director Fund project of Key Laboratory of Cognitive Radio and Information Processing of Ministry of Education(No.CRKL190102)。
文摘The proliferation of the global datasphere has forced cloud storage systems to evolve more complex architectures for different applications.The emergence of these application session requests and system daemon services has created large persistent flows with diverse performance requirements that need to coexist with other types of traffic.Current routing methods such as equal-cost multipath(ECMP)and Hedera do not take into consideration specific traffic characteristics nor performance requirements,which make these methods difficult to meet the quality of service(QoS)for high-priority flows.In this paper,we tailored the best routing for different kinds of cloud storage flows as an integer programming problem and utilized grey relational analysis(GRA)to solve this optimization problem.The resulting method is a GRAbased service-aware flow scheduling(GRSA)framework that considers requested flow types and network status to select appropriate routing paths for flows in cloud storage datacenter networks.The results from experiments carried out on a real traffic trace show that the proposed GRSA method can better balance traffic loads,conserve table space and reduce the average transmission delay for high-priority flows compared to ECMP and Hedera.
