Three-Dimensional Topological Insulator in a Magnetic Field: Chiral Side Surface States and Quantized Hall Conductance

Low energy excitation of surface states of a three-dimensional topological insulator (3DTI) can be described by Dirac fermions. By using a tight-binding model, the transport properties of the surface states in a uniform magnetic field is investigated. It is found that chiral surface states parallel to the magnetic field are responsible to the quantized Hall (QH) conductance $(2n+1)\frac{e^2}{h}$ multiplied by the number of Dirac cones. Due to the two-dimension (2D) nature of the surface states, the robustness of the QH conductance against impurity scattering is determined by the oddness and evenness of the Dirac cone number. An experimental setup for transport measurement is proposed

Thermodynamical quantities of lattice full QCD from an efficient method

I extend to QCD an efficient method for lattice gauge theory with dynamical fermions. Once the eigenvalues of the Dirac operator and the density of states of pure gluonic configurations at a set of plaquette energies (proportional to the gauge action) are computed, thermodynamical quantities deriving from the partition function can be obtained for arbitrary flavor number, quark masses and wide range of coupling constants, without additional computational cost. Results for the chiral condensate and gauge action are presented on the $10^4$ lattice at flavor number $N_f=0$, 1, 2, 3, 4 and many quark masses and coupling constants. New results in the chiral limit for the gauge action and its correlation with the chiral condensate, which are useful for analyzing the QCD chiral phase structure, are also provided.Comment: Latex, 11 figures, version accepted for publicatio

Bulk Rotational Symmetry Breaking in Kondo Insulator SmB6

Kondo insulator samarium hexaboride (SmB6) has been intensely studied in recent years as a potential candidate of a strongly correlated topological insulator. One of the most exciting phenomena observed in SmB6 is the clear quantum oscillations appearing in magnetic torque at a low temperature despite the insulating behavior in resistance. These quantum oscillations show multiple frequencies and varied effective masses. The origin of quantum oscillation is, however, still under debate with evidence of both two-dimensional Fermi surfaces and three-dimensional Fermi surfaces. Here, we carry out angle-resolved torque magnetometry measurements in a magnetic field up to 45 T and a temperature range down to 40 mK. With the magnetic field rotated in the (010) plane, the quantum oscillation frequency of the strongest oscillation branch shows a four-fold rotational symmetry. However, in the angular dependence of the amplitude of the same branch, this four-fold symmetry is broken and, instead, a twofold symmetry shows up, which is consistent with the prediction of a two-dimensional Lifshitz-Kosevich model. No deviation of Lifshitz-Kosevich behavior is observed down to 40 mK. Our results suggest the existence of multiple light-mass surface states in SmB6, with their mobility significantly depending on the surface disorder level.Comment: 15 pages, 9 figure

In an Attempt to Introduce Long-range Interactions into Small-world Networks

Distinguishing the long-range bonds with the regular ones, the critical temperature of the spin-lattice Guassian model built on two typical Small-world Networks (SWNs) is studied. The results show much difference from the classical case, and thus may induce some more accurate discussion on the critical properties of the spin-lattice systems combined with the SWNs.Comment: 4 pages, 3 figures, 18 referenc

Numerical investigation of added mass coefficient of a subsea manifold in the accelerating flow and oscillating flow

The hydrodynamic forces and dynamic responses of subsea equipment, like manifolds, are significantly affected by the motions of the mothership or the unexpected incoming underwater flows like current or internal wave. In this paper, the hydrodynamic coefficients of a simplified subsea manifold, a submerged 3D prism are predicted through the constant acceleration method and forced oscillating method, which are both implemented by the CFD simulation approach. The three directional added mass coefficients of the prism in accelerating flow with different accelerations are obtained. But the value of constant acceleration is found not significantly influencing the added mass coefficient of the rectangular prism. The added mass coefficient of the rectangular prism studied in the paper is 0.233, 0.395, and 2.191 in X, Y and Z direction, respectively. In order to predict the added mass coefficient of the 3D rectangular prism in oscillating flow, the forced oscillating method is used to simulate the rectangular prism oscillating in three directions (X, Y, Z) under different oscillating amplitude and frequency

Analysis and Criterion for Inherent Balance Capability in Modular Multilevel DC–AC–DC Converters

Modular multilevel dc-ac-dc converters (MMDAC) have emergedrecently for high step-ratio connectionsin medium voltage distribution systems.Extended phase-shiftmodulation has been proposed and was found to create the opportunity for inherent balance of SM capacitor voltages. This letter presents fundamentalanalysis leading toclear criterion for the inherent balancecapability in MMDAC. A sufficient and necessary condition,with associated assumptions,to guarantee this capability isestablished. Using the mathematics of circulant matrices, this condition is simplified to a co-prime criterion which gives rise to practical guidance for the design of an MMDAC. Experimentson down-scaled prototypesand simulations on full-scale examples both provide verification of the analysis and criterion for the inherent balance capability of MMDAC

Numerical investigation of added mass coefficient of a subsea manifold in the accelerating flow and oscillating flow

944-953The hydrodynamic forces and dynamic responses of subsea equipment, like manifolds, are significantly affected by the motions of the mothership or the unexpected incoming underwater flows like current or internal wave. In this paper, the hydrodynamic coefficients of a simplified subsea manifold, a submerged 3D prism are predicted through the constant acceleration method and forced oscillating method, which are both implemented by the CFD simulation approach. The three directional added mass coefficients of the prism in accelerating flow with different accelerations are obtained. But the value of constant acceleration is found not significantly influencing the added mass coefficient of the rectangular prism. The added mass coefficient of the rectangular prism studied in the paper is 0.233, 0.395, and 2.191 in X, Y and Z direction, respectively. In order to predict the added mass coefficient of the 3D rectangular prism in oscillating flow, the forced oscillating method is used to simulate the rectangular prism oscillating in three directions (X, Y, Z) under different oscillating amplitude and frequency