A systematic study of the two-dimensional electron gas at La AlO_3/SrTiO_3(110) interface reveals an anisotropy along two specific directions, [001] and 1ī0. The anisotropy becomes distinct for the interface prepared under high oxygen pressure with low carrier density. Angular dependence of magnetoresistance shows that the electron confinement is stronger along the 1ī0 direction. Gate-tunable magnetoresistance reveals a clear in-plane anisotropy of the spin–orbit coupling,and the spin relaxation mechanism along both directions belongs to D'yakonov–Perel'(DP) scenario. Moreover, in-plane anisotropic superconductivity is observed for the sample with high carrier density, the superconducting transition temperature is lower but the upper critical field is higher along the 1ī0 direction. This in-plane anisotropy could be ascribed to the anisotropic band structure along the two crystallographic directions.
The structures and stabilization of three crystal surfaces of TCNQ-based charge transfer complexes(CTCs) including PrQ(TCNQ) 2,MPM(TCNQ) 2,and MEM(TCNQ) 2,have been investigated by scanning tunneling microscopy(STM).The three bulk-truncated surfaces are all ac-surface,which are terminated with TCNQ molecular arrays.On the ac-surface of PrQ(TCNQ) 2,the TCNQ molecules form a tetramer structure with a wavelike row behavior and a γ angle of about 18° between adjacent molecules.Moreover,the dimer structures are resolved on both ac-surfaces of MPM(TCNQ) 2 and MEM(TCNQ) 2.In addition,the tetramer structure is the most stable structure,while the dimer structures are unstable and easily subject to the STM tip disturbance,which results in changeable unit cells.The main reasons for the surface stabilization variation among the three ac-surfaces are provided by using the 'π-atom model'.
A laser scanning confocal imaging-surface plasmon resonance (LSCI-SPR) instrument integrated with a wavelength-dependent surface plasmon resonance (SPR) sensor and a laser scanning confocal microscopy (LSCM) is built to detect the bonding process of human IgG and fluorescent-labeled affinity purified antibodies in real time.The shifts of resonant wavelength at different reaction time stages are obtained by SPR,corresponding well with the changes of the fluorescence intensity collected by using LSCM.The instrument shows the merits of the combination and complementation of the SPR and LSCM,with such advantages as quantificational analysis,high spatial resolution and real time monitor,which are of great importance for practical applications in biosensor and life science.
