Phase diagram of doped BaFe2_2As2_2 superconductor under broken C4C_4 symmetry

We develop a minimal multiorbital tight-binding model with realistic hopping parameters. The model breaks the symmetry of the tetragonal point group by lowering it from $C_4$ to $D_{2d}$, which accurately describes the Fermi surface evolution of the electron-doped BaFe$_{2-x}$Co$_x$As$_2$ and hole-doped Ba$_{1-y}$K$_y$Fe$_2$As$_2$ compounds. An investigation of the phase diagram with a mean-field $t$-$U$-$V$ Bogoliubov-de Gennes Hamiltonian results in agreement with the experimentally observed electron- and hole-doped phase diagram with only one set of $t$, $U$ and $V$ parameters. Additionally, the self-consistently calculated superconducting order parameter exhibits $s^\pm$-wave pairing symmetry with a small d-wave pairing admixture in the entire doping range, % The superconducting $s^\pm + d$-wave order parameter which is the subtle result of the weakly broken symmetry and competing interactions in the multiorbital mean-field Hamiltonian

COVID-19 accelerated digital transformation: The case of Meituan

The outbreak of the COVID-19 pandemic caused disruptions in supply chains. While most existing research suggests ways to improve organizational resilience, our research raises the question of whether the pandemic has accelerated digital transformation at the organizational level. Using the case of Meituan in China, we investigate the supply chain disruptions caused by COVID-19, the strategies taken by Meituan to address the problems and their strategic implications. Starting as a fast food delivery company, Meituan has developed into a leading online shopping platform in China specialized in using digital technologies to provide on-demand delivery services. Our research on Meituan during COVID-19 shows that companies can leverage emerging technologies to improve business models and deliver long-term strategic benefits through digital transformation, rather than focusing solely on improving organizational resilience to reduce uncertainty risk