Electroweak Corrections to the Decays of Stop and Gluino

The electroweak corrections at the order of $O(\alpha_{ew}m_{t(b)}^2/m_W^2)$ to the partial widths of the $\tilde{t}_2 \to \tilde{g} + t$ and $\tilde{g} \to \tilde{t}_1 + \bar{t}$ decays (depending on the masses of the particles involved) are investigated within the Supersymmetric Standard Model. The relative corrections can reach the value of 10% in some parameter space, which can be comparable with the corresponding QCD corrections. Therefore, they should be taken into account for the precise experimental measurement at future colliders.Comment: 15 pages, 5 figures, Physical Review D publication versio

Mechanism of Polarization Fatigue in BiFeO3: the Role of Schottky Barrier

By using piezoelectric force microscopy and scanning Kelvin probe microscopy, we have investigated the domain evolution and space charge distribution in planar BiFeO3 capacitors with different electrodes. It is observed that charge injection at the film/electrode interface leads to domain pinning and polarization fatigue in BiFeO3. Furthermore, the Schottky barrier at the interface is crucial for the charge injection process. Lowering the Schottky barrier by using low work function metals as the electrodes can also improve the fatigue property of the device, similar to what oxide electrodes can achieve

Non-commutative Solitons in Finite Quantum Mechanics

We construct the unitary evolution operators that realize the quantization of linear maps of SL(2,R) over phase spaces of arbitrary integer discretization N and show the non-trivial dependence on the arithmetic nature of N. We discuss the corresponding uncertainty principle and construct the corresponding coherent states, that may be interpreted as non-commutative solitons.Comment: 3 pages LaTeX. Uses espcrc2.sty and amssymb.sty. Contribution to Lattice 2002(theoretical

China's New-Type Urbanisation Plan (NUP) and the foreseeing challenges for decarbonization of cities: a review

The most recent urbanisation plan in China, the New-type Urbanisation Plan (NUP) launched in March 2014, is a national plan proposed for development of a scientific and reasonable urban development model by 2020. NUP aims to connect four major plans of ecological progress, urbanisation quality, expanding domestic demand and rural-urban coordination. After almost two years, several contradictions are already in place. However, there are key challenges for decarbonization of cities in this process. This review paper explores four major challenges and suggests steps forward during and after NUP's lifespan. This study also elaborates on the processes and contradictions for decarbonization of Chinese cities

Coexistence of Ferroelectric Triclinic Phases and Origin of Large Piezoelectric Responses in Highly Strained BiFeO3 films

The structural evolution of the strain-driven morphotropic phase boundary (MPB) in BiFeO3 films has been investigated using synchrotron x-ray diffractometry in conjunction with scanning probe microscopy. Our results demonstrate the existence of mixed-phase regions that are mainly made up of two heavily tilted ferroelectric triclinic phases. Analysis of first-principles computations suggests that these two triclinic phases originate from a phase separation of a single monoclinic state accompanied by elastic matching between the phase-separated states. These first-principle calculations further reveal that the intrinsic piezoelectric response of these two low-symmetry triclinic phases is not significantly large, which thus implies that the ease of phase transition between these two energetically close triclinic phases is likely responsible for the large piezoelectric response found in the BiFeO3 films near its MPB. These findings not only enrich the understandings of the lattice and domain structure of epitaxial BiFeO3 films but may also shed some light on the origin of enhanced piezoelectric response near MPB.Comment: 19 pages, 3 figures and 1 tabl

Coherent transmission through a one dimensional lattice

Based on the Keldysh nonequilibrium Green function (NGF) technique, a general formula for the current and transmission coefficient through a one dimensional lattice is derived without the consideration of electron-electron interactions. We obtain an analytical condition for perfect resonant transmission when the levels of sites are aligned, which depends on the parity of the number of sites. Localization-delocalization transition in a generic one dimensional disordered lattice is also analyzed, depending on the correlation among the hopping parameters and the strength of the coupling to reservoirs. The dependence of the number and lineshape of resonant transmission and linear conductance peaks on the structure parameters of the lattice is also given in several site cases.Comment: 22 pages, 3 figures, Revtex, minor revision mad