The magnetic states of the strongly correlated system plutonium dioxide(PuO_(2)) are studied based on the density functional theory(DFT) plus Hubbard U(DFT +U) method with spin–orbit coupling(SOC) included. A series ...The magnetic states of the strongly correlated system plutonium dioxide(PuO_(2)) are studied based on the density functional theory(DFT) plus Hubbard U(DFT +U) method with spin–orbit coupling(SOC) included. A series of typical magnetic structures including the multiple-k types are simulated and compared in the aspect of atomic structure and total energy. We test LDA, PBE, and SCAN exchange–correlation functionals on PuO_(2) and a longitudinal 3k antiferromagnetic(AFM) ground state is theoretically determined. This magnetic structure has been identified to be the most stable one by the former computational work using the hybrid functional. Our DFT +U + SOC calculations for the longitudinal 3k AFM ground state suggest a direct gap which is in good agreement with the experimental value. In addition, a genetic algorithm is employed and proved to be effective in predicting magnetic ground state of PuO2. Finally, a comparison between the results of two extensively used DFT +U approaches to this system is made.展开更多
We theoretically provide a magnetic phase diagram for the single-layer(SL)CrBr_(3),which could be effectively tuned by both strain engineering and charge doping in SL-CrBr_(3).Through systematical first-principles cal...We theoretically provide a magnetic phase diagram for the single-layer(SL)CrBr_(3),which could be effectively tuned by both strain engineering and charge doping in SL-CrBr_(3).Through systematical first-principles calculations and Heisenberg model Hamiltonian simulations,three different magnetic phases in SL-CrBr_(3),which are off-plane ferromagnetic,in-plane ferromagnetic and in-plane Neél-antiferromagnetic phases,are found in the strain and charge doping regimes we studied.Furthermore,our results show that higher order Heisenberg exchange parameters and anisotropy exchange parameters should be taken into account for accurately illustrating the magnetic phase transition in SL-CrBr_(3).As a result,we find from the SpinW simulation that the Curie temperature is about T_(c)=38.4 K,which is well consistent with the experimental result 34 K[Nano Lett.193138(2019)].The findings here may be confirmed in future experiments,and may be useful for the potential applications of SL-CrBr_(3)in spintronics field.展开更多
We propose an interferometer composing of a scanning tunneling microscope(STM),double quantum dots(DQDs),and a semiconductor nanowire carrying Majorana bound states(MBSs)at its ends induced by the proximity effect of ...We propose an interferometer composing of a scanning tunneling microscope(STM),double quantum dots(DQDs),and a semiconductor nanowire carrying Majorana bound states(MBSs)at its ends induced by the proximity effect of an s-wave superconductor,to probe the existence of the MBSs in the dots.Our results show that when the energy levels of DQDs are aligned to the energy of MBSs,the zero-energy spectral functions of DQDs are always equal to 1/2,which indicates the formation of the MBSs in the DQDs and is also responsible for the zero-bias conductance peak.Our findings suggest that the spectral functions of the DQDs may be an excellent and convenient quantity for detecting the formation and stability of the spatially separated MBSs in quantum dots.展开更多
基金supported by National Natural Science Foundation of China, (Grant No. 12104034)。
文摘The magnetic states of the strongly correlated system plutonium dioxide(PuO_(2)) are studied based on the density functional theory(DFT) plus Hubbard U(DFT +U) method with spin–orbit coupling(SOC) included. A series of typical magnetic structures including the multiple-k types are simulated and compared in the aspect of atomic structure and total energy. We test LDA, PBE, and SCAN exchange–correlation functionals on PuO_(2) and a longitudinal 3k antiferromagnetic(AFM) ground state is theoretically determined. This magnetic structure has been identified to be the most stable one by the former computational work using the hybrid functional. Our DFT +U + SOC calculations for the longitudinal 3k AFM ground state suggest a direct gap which is in good agreement with the experimental value. In addition, a genetic algorithm is employed and proved to be effective in predicting magnetic ground state of PuO2. Finally, a comparison between the results of two extensively used DFT +U approaches to this system is made.
基金Project supported by the National Natural Science Foundation of China(Grant No.11625415)the Innovation Development Foundation of China Academy of Engineering Physics(Grant No.ZYCX1921-02)。
文摘We theoretically provide a magnetic phase diagram for the single-layer(SL)CrBr_(3),which could be effectively tuned by both strain engineering and charge doping in SL-CrBr_(3).Through systematical first-principles calculations and Heisenberg model Hamiltonian simulations,three different magnetic phases in SL-CrBr_(3),which are off-plane ferromagnetic,in-plane ferromagnetic and in-plane Neél-antiferromagnetic phases,are found in the strain and charge doping regimes we studied.Furthermore,our results show that higher order Heisenberg exchange parameters and anisotropy exchange parameters should be taken into account for accurately illustrating the magnetic phase transition in SL-CrBr_(3).As a result,we find from the SpinW simulation that the Curie temperature is about T_(c)=38.4 K,which is well consistent with the experimental result 34 K[Nano Lett.193138(2019)].The findings here may be confirmed in future experiments,and may be useful for the potential applications of SL-CrBr_(3)in spintronics field.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11564029 and 11675023)the Natural Science Foundation of Inner Mongolia,China(Grant No.2017MS0112)+3 种基金the Science Foundation for Excellent Youth Scholors of Inner Mongolia University of Science and Technology,China(Grant No.2017YQL06)the Initial Project of UEST of China,Zhongshan Institute(Grant No.415YKQ02)the Science and Technology Bureau of Zhongshan City,China(Grant Nos.2017B1116 and 2017B1016)the Innovation Team of Zhongshan City,China(Grant No.180809162197886).
文摘We propose an interferometer composing of a scanning tunneling microscope(STM),double quantum dots(DQDs),and a semiconductor nanowire carrying Majorana bound states(MBSs)at its ends induced by the proximity effect of an s-wave superconductor,to probe the existence of the MBSs in the dots.Our results show that when the energy levels of DQDs are aligned to the energy of MBSs,the zero-energy spectral functions of DQDs are always equal to 1/2,which indicates the formation of the MBSs in the DQDs and is also responsible for the zero-bias conductance peak.Our findings suggest that the spectral functions of the DQDs may be an excellent and convenient quantity for detecting the formation and stability of the spatially separated MBSs in quantum dots.
