d

Ground-state properties of the attractive one-dimensional Bose-Hubbard model

“…This so called root tracking works well if the root set {k i }| Γ+∆ is similar to the previous step {k i }| Γ -for a close initial guess most non-linear solver have good convergence. From the above it can be seen that this method is unsuitable for the study of large N behavior -the root pattern is expected to change strongly when crossing over the pre-transition at Γ c = π 2 , which is in accordance with findings of Sakman et al 11 . In a diagram N vs. Γ the above method corresponds to moving along horizontal lines, where in the left part the root distribution is asymptotically of semi-circle shape, while on the right side it has the uniform box shape.…”

“…While repulsive boson systems, as well as repulsive and attractive fermion systems are well studied in the context of solvable systems the attractive boson gas received comparatively little attention 11 . Still the seminal Bethe Ansatz solution for one-dimensional contact interaction bosons 16 in the continuum describes the repulsive as well as the attractive regime, in which the solutions to the Bethe Ansatz equations become of different character 40 .…”

“…The substantial amount of research undertaken recently 4,5,6,7,8,9,10,11 poses new questions surrounding systems of attractive bosons. An almost ideal realisation of a lattice Bose gas -the Bose-Hubbard model -has been found in bosons trapped inside optical lattices 12 .…”

Large and robust electrical spin injection into GaAs at zero magnetic field using an ultrathin CoFeB/MgO injector

“…Potential devices ranging from memory element with optical readout and optical transport of spin information 3 , advanced optical switches 4 , circularly polarized single photon emitters for quantum cryptography 5 to chiral analysis 6 and 3-dimensional display screens 7 have been anticipated. According to the optical selection rules 8 in quantum well (QW)-based spin LEDs, conventional spin-injector with in-plane magnetization [9][10][11][12][13][14][15][16][17][18] cannot satisfy the practical application because a strong external magnetic field in the range of up to a few Tesla is required to rotate the magnetization into a perpendicular direction.…”

Selective calcium ion detection with functionalized ZnO nanorods-extended gate MOSFET

“…ZnO nanostructures have also attracted considerable attention as a sensing material with great potential in various applications. ZnO nanorods specifically, have shown to be useful for electrical detection of biological species with high sensitivity (Wei et al, 2006;Kumar et al, 2006;Kim et al, 2006;Liu et al, 2006;Zhang et al, 2004;Huang and Choi, 2007). ZnO based nanosensors have previously been applied as pH sensors and for gas sensing (Tien et al, 2007;Al-Hilli et al, 2006;Kang et al, 2005;Gao and Wang, 2005;Wang et al, 2004;Fan et al, 2004).…”