arXiv subjects

Wang Gang

Publications and source records attributed to Wang Gang.

3 recordsLinked to original sources

arXiv2026

Growth and hydrostatic-pressure study of a type-II superconductor Bi$_2$Ta$_3$S$_6$ single crystal

We report the growth and physical properties of single-crystalline Bi$_2$Ta$_3$S$_6$ crystallizing in $P6_3/mcm$ space group, which comprises alternating Ta-S layers and Bi layers with each Bi atom connected with adjacent S atoms. Temperature-dependent electrical resistivity measurements reveal a superconducting transition at 0.84 K, with upper critical field 231 Oe under an out-of-plane magnetic field. The magnetization measurements confirm its nature as a type-II superconductor, with anisotropic Ginzburg-Landau parameter $\kappa_{ab}$ = 7.67 and $\kappa_c$ = 4.50. Hall measurements indicate the dominant carriers as hole. Hydrostatic pressure is applied, under which both the superconducting transition temperature and upper critical field increase sharply under low pressure before undergoing slight suppression under higher pressure. Density functional theory calculations reveal non-trivial topological surface states on (100) surface in Bi$_2$Ta$_3$S$_6$, which may offer a new avenue for exploring potential topological superconductivity in layered transition metal dichalcogenides.

cond-mat.supr-con↗

arXiv2023

The bistability of curved compression ramp flows

This paper investigates the bistability of curved compression ramp (CCR) flows. It reports that both separated and attached states can be stably established even for the same boundary conditions, revealing that the ultimate stable states of CCR flows also depend on the initial conditions and evolutionary history. Firstly, we design a thought experiment involving two establishment routes of CCR flows, constructing two distinct-different stable states, respectively. Subsequently, three-dimensional direct numerical simulations are meticulously performed to instantiate the thought experiment, verifying the existence of the bistable states. Finally, we compare the pressure, wall friction, and heat flux distributions under two stable states. As a canonical type of Shock wave-Boundary layer interactions, local CCR flows often appear on aircraft, hence the bistability will certainly bring noteworthy changes to the global aerothermodynamic characteristics, which supersonic/hypersonic flight has to deal with.

physics.flu-dyn↗

arXiv2011

The Price of Anarchy (POA) of network coding and routing based on average pricing mechanism

The congestion pricing is an efficient allocation approach to mediate demand and supply of network resources. Different from the previous pricing using Affine Marginal Cost (AMC), we focus on studying the game between network coding and routing flows sharing a single link when users are price anticipating based on an Average Cost Sharing (ACS) pricing mechanism. We characterize the worst-case efficiency bounds of the game compared with the optimal, i.e., the price-of anarchy (POA), which can be low bound 50% with routing only. When both network coding and routing are applied, the POA can be as low as 4/9. Therefore, network coding cannot improve the POA significantly under the ACS. Moreover, for more efficient use of limited resources, it indicates the sharing users have a higher tendency to choose network coding.

cs.NI↗