In this paper we investigate classical and quantum phase transitions of Bose-Hubbard model in checkerboard superlattices with a magnetic field at the mean-field level. By analyzing stability of normal state phase boun...In this paper we investigate classical and quantum phase transitions of Bose-Hubbard model in checkerboard superlattices with a magnetic field at the mean-field level. By analyzing stability of normal state phase boundaries are obtained analytically for zero and finite temperature in a unified theoretical frame and easily extended to the situation without the magnetic field. All results illustrate that the introduction of the magnetic field enhances the stability of normal state and Mort insulator. In addition we also note that the critical hopping term presents an oscillating behavior inversely following the upper boundary of Hofstadter butterfly.展开更多
Based on the crystal plasticity theory and interatomic potential, in this paper a new thermo-elasto-plasticity constitutive model is proposed to study the behavior of metal crystals at finite temperature. By applying ...Based on the crystal plasticity theory and interatomic potential, in this paper a new thermo-elasto-plasticity constitutive model is proposed to study the behavior of metal crystals at finite temperature. By applying the present constitutive model, the stress-strain curves under uniaxial tension at different temperatures are calculated for the typical crystal A1, and the calculated results are compared with the experimental results. From the comparisons, it can be seen that the present theory has the capability to describe the thermo-elasto-plastic behavior of metal crystals at finite temperature through a concise and explicit calculation process.展开更多
基金Supported by National Natural Science Foundation of China under Grant No.10675108Foundation of Yancheng Institute of Technology under Grant No.XKR2010007
文摘In this paper we investigate classical and quantum phase transitions of Bose-Hubbard model in checkerboard superlattices with a magnetic field at the mean-field level. By analyzing stability of normal state phase boundaries are obtained analytically for zero and finite temperature in a unified theoretical frame and easily extended to the situation without the magnetic field. All results illustrate that the introduction of the magnetic field enhances the stability of normal state and Mort insulator. In addition we also note that the critical hopping term presents an oscillating behavior inversely following the upper boundary of Hofstadter butterfly.
基金supported by the National Natural Science Foundation of China(Grant Nos.11021262,11172303 and 11132011)National Basic Research Program of China(Grant No.2012CB937500)
文摘Based on the crystal plasticity theory and interatomic potential, in this paper a new thermo-elasto-plasticity constitutive model is proposed to study the behavior of metal crystals at finite temperature. By applying the present constitutive model, the stress-strain curves under uniaxial tension at different temperatures are calculated for the typical crystal A1, and the calculated results are compared with the experimental results. From the comparisons, it can be seen that the present theory has the capability to describe the thermo-elasto-plastic behavior of metal crystals at finite temperature through a concise and explicit calculation process.
