We investigate the Hall effects of quadratic band crossing(QBC) fermions in a square optical lattice with spin–orbit coupling and orbital Zeeman term. We find that the orbital Zeeman term and shaking play critical ro...We investigate the Hall effects of quadratic band crossing(QBC) fermions in a square optical lattice with spin–orbit coupling and orbital Zeeman term. We find that the orbital Zeeman term and shaking play critical roles in the systems,which can drive a topological transition from spin Hall phases to anomalous Hall phase with nonvanishing(spin) Chern numbers. Due to the interplay among the orbital Zeeman term, spin–orbit coupling, and the shaking, the phase diagram of the system exhibits rich phases, which are characterized by Chern number.展开更多
High-spin states in 139Nd nucleus have been reinvestigated with the reaction 128Te (16O, 5n) at a beam energy of 90 MeV. The level scheme has been expanded with spin up to 47/2 . At the low spin states, the yrast coll...High-spin states in 139Nd nucleus have been reinvestigated with the reaction 128Te (16O, 5n) at a beam energy of 90 MeV. The level scheme has been expanded with spin up to 47/2 . At the low spin states, the yrast collective structure built on the νh11/2-1 multiplet shows a transitional shape with γ ≈ 32° according to calculations of the triaxial rotor-plus-particle model. Three collective oblate bands with γ ～-60° at the high spin states were identified for the first time. A band crossing is observed around ω ～0.4 MeV in one oblate band based on the 25/2-level.展开更多
Excited states in the odd-proton nucleus 125Cs were investigated by means of in-beam β-ray spectroscopy. The πg7/2 band is observed to fork into a △I = 1 coupled band and a △I = 2 decoupled band at high spins. To ...Excited states in the odd-proton nucleus 125Cs were investigated by means of in-beam β-ray spectroscopy. The πg7/2 band is observed to fork into a △I = 1 coupled band and a △I = 2 decoupled band at high spins. To assign the possible configurations of these two bands, experimental B（M1）/B（E2） ratios and signature splittings have been evaluated for the △I = 1 band, and calculations based on the geometrical model, cranked shell model and total Routhian surfaces model have been performed. They are suggested to be a near-oblate band built on the （πg7/2/d5/2） （vh11/2）2 configuration and a prolate band built on the πg7/2 （πh11/2）2 configuration, respectively.展开更多
High-spin yrast structures of even-even superheavy nuclei 254-25SRf are investigated by means of total- Routhian-surface approach in three-dimensional （f12, 7, f14） space. The behavior in the moments of inertia of 2...High-spin yrast structures of even-even superheavy nuclei 254-25SRf are investigated by means of total- Routhian-surface approach in three-dimensional （f12, 7, f14） space. The behavior in the moments of inertia of 256Rf is well reproduced by our calculations, which is attributed to the J15/2 neutron rotation-alignment. The competition between the rotationally aligned ila/2 proton and j15/2 neutron may occur to a large extent in 256Rf. High-spin predictions are also made for its neighboring isotopes 254＇2ssRf, showing that the alignment of the j15/2 neutron pair is more favored than that of the i13/2 proton pair.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 11504095)。
文摘We investigate the Hall effects of quadratic band crossing(QBC) fermions in a square optical lattice with spin–orbit coupling and orbital Zeeman term. We find that the orbital Zeeman term and shaking play critical roles in the systems,which can drive a topological transition from spin Hall phases to anomalous Hall phase with nonvanishing(spin) Chern numbers. Due to the interplay among the orbital Zeeman term, spin–orbit coupling, and the shaking, the phase diagram of the system exhibits rich phases, which are characterized by Chern number.
基金Supported by National Natural Science Foundation of China (10575057, 10775078)Major State Basic Research Development Program (2007CB815005)Special Program of Higher Education Science Foundation (20070003149)
文摘High-spin states in 139Nd nucleus have been reinvestigated with the reaction 128Te (16O, 5n) at a beam energy of 90 MeV. The level scheme has been expanded with spin up to 47/2 . At the low spin states, the yrast collective structure built on the νh11/2-1 multiplet shows a transitional shape with γ ≈ 32° according to calculations of the triaxial rotor-plus-particle model. Three collective oblate bands with γ ～-60° at the high spin states were identified for the first time. A band crossing is observed around ω ～0.4 MeV in one oblate band based on the 25/2-level.
基金Supported in part by National Natural Science Foundation of China(11475072)
文摘Excited states in the odd-proton nucleus 125Cs were investigated by means of in-beam β-ray spectroscopy. The πg7/2 band is observed to fork into a △I = 1 coupled band and a △I = 2 decoupled band at high spins. To assign the possible configurations of these two bands, experimental B（M1）/B（E2） ratios and signature splittings have been evaluated for the △I = 1 band, and calculations based on the geometrical model, cranked shell model and total Routhian surfaces model have been performed. They are suggested to be a near-oblate band built on the （πg7/2/d5/2） （vh11/2）2 configuration and a prolate band built on the πg7/2 （πh11/2）2 configuration, respectively.
基金Supported by National Natural Science Foundation of China(10805040,11175217)Foundation and Advanced Technology Research Program of Henan Province(132300410125)S&T Research Key Program of Henan Province Education Department(13A140667)
文摘High-spin yrast structures of even-even superheavy nuclei 254-25SRf are investigated by means of total- Routhian-surface approach in three-dimensional （f12, 7, f14） space. The behavior in the moments of inertia of 256Rf is well reproduced by our calculations, which is attributed to the J15/2 neutron rotation-alignment. The competition between the rotationally aligned ila/2 proton and j15/2 neutron may occur to a large extent in 256Rf. High-spin predictions are also made for its neighboring isotopes 254＇2ssRf, showing that the alignment of the j15/2 neutron pair is more favored than that of the i13/2 proton pair.
