Chiral Charge Density Wave and Backscattering-Immune Orbital Texture in Monolayer 1T-TiTe2.

Nontrivial electronic states are attracting intense attention in low-dimensional physics. Though chirality has been identified in charge states with a scalar order parameter, its intertwining with charge density waves (CDW), film thickness, and the impact on the electronic behaviors remain less well understood. Here, using scanning tunneling microscopy, we report a 2 × 2 chiral CDW as well as a strong suppression of the Te-5p hole-band backscattering in monolayer 1T-TiTe2. These exotic characters vanish in bilayer TiTe2 in a non-CDW state. Theoretical calculations prove that chirality comes from a helical stacking of the triple-q CDW components and, therefore, can persist at the two-dimensional limit. Furthermore, the chirality renders the Te-5p bands with an unconventional orbital texture that prohibits electron backscattering. Our study establishes TiTe2 as a promising playground for manipulating the chiral ground states at the monolayer limit and provides a novel path to engineer electronic properties from an orbital degree.

Quantum spin driven Yu-Shiba-Rusinov multiplets and fermion-parity-preserving phase transition in K3C60.

Magnetic impurities in superconductors are of increasing interest due to emergent Yu-Shiba-Rusinov (YSR) states and Majorana zero modes for fault-tolerant quantum computation. However, a direct relationship between the YSR multiple states and magnetic anisotropy splitting of quantum impurity spins remains poorly characterized. By using scanning tunneling microscopy, we systematically resolve individual transition-metal (Fe, Cr, and Ni) impurities induced YSR multiplets as well as their Zeeman effects in the K3C60 superconductor. The YSR multiplets show identical d orbital-like wave functions that are symmetry-mismatched to the threefold K3C60(1 1 1) host surface, breaking point-group symmetries of the spatial distribution of YSR bound states in real space. Remarkably, we identify an unprecedented fermion-parity-preserving quantum phase transition between ground states with opposite signs of the uniaxial magnetic anisotropy that can be manipulated by an external magnetic field. These findings can be readily understood in terms of anisotropy splitting of quantum impurity spins, and thus elucidate the intricate interplay between the magnetic anisotropy and YSR multiplets.

Characterization and expression profiles of muscle transcriptome in Schizothoracine fish, Schizothorax prenanti.

Schizothorax prenanti is a cold-water fish species with great economic importance in aquaculture in Western China, and the underlying mechanisms of muscle development and growth in S. prenanti remain to be elucidated. In this study, deep RNA sequencing was performed to provide an in-depth view of the transcriptome of skeletal muscle of S. prenanti with the specific objective to identify expressed genes in the skeletal muscle of S. prenanti at 30 days post-hatching (S01), 1 year (S02), and 3 years (S03). De novo assembly of high-quality reads generated 132,784 transcripts with an average length of 1282 bp and 67,596 unigenes with an average length of 1559 bp. 2445 unigenes were differentially expressed with 1483 up-regulated and 962 down-regulated in the skeletal muscle of S. prenanti at S01 and S02 stages, and 1936 unigenes were significantly impacted at S02 and S03 stages with 1153 increased and 783 decreased. GO analysis showed that the differentially expressed genes are involved in various biological processes with dominance by cell & cell part, binding & catalytic activity, and cellular process & metabolic process. KEGG enrichment suggested that there are considerable differences in the physiological processes at different stages of muscle development and growth of S. prenanti. PPAR signaling pathway, cardiac muscle contraction, fatty acid metabolism, tight junction, and focal adhesion were the top pathways enriched in comparison between S01 and S02 stages. Whereas significant enrichment of the TCA cycle, fatty acid metabolism, fatty acid elongation in mitochondria, valine, leucine and isoleucine degradation, porphyrin and chlorophyll metabolism, and propanoate metabolism pathway was found in differentially expressed genes identified between S02 and S03 stages. This study provides not only an overall insight into the global gene expression landscape in the skeletal muscle of S. prenanti, but also candidate genes or markers that can be used for further investigations of the underlying mechanisms of skeletal muscle development and growth of S. prenanti.