Instanton-induced effects in interquark forces, light-front wave functions and formfactors

Exclusive processes are traditionally described by perturbative hard blocks and “distribution amplitudes" (DAs), matrix elements of operators of various chiral structure and twist. One paper (with I.Zahed) calculate instanton contribution to hard blocks, which is found comparable to perturbative one in few-GeV2 Q2 region of interest. Another paper aims at comprehensive wave functions of mesons, baryons and pentaquarks. The last ones are also included as 5-quark component of the baryons. The calculation, using ’t Hooft operator, gives x-dependence and magnitude of the antiquark PDF. It explains long standing issue of strong flavor asymmetry of antiquark sea. The third paper (also with I.Zahed) is semi-review on the instanton-sphaleron processes in QCD and electroweak theories, with emphasis on their possible experimental observation via double diffractive events at LHC and RHIC. Insert your english abstract here.

Structural material with designed thermal twist for a simple actuation

Materials with desired thermal deformation are very important for various engineering applications. Here, a material with the combination of chiral structure and TiNi shape memory alloy (SMA) sheets that performs a twist during heating is proposed. The thermo-mechanical properties of these materials are experimentally investigated. Inspired by this, a car-like material performing translational and rotational motion is designed, which illustrates the potential applications for the next-generation soft robotic devices. Based on this method, one can design remotely manipulated artificial muscles, nanorobots, revolute pairs, and thermal sensors or actuators in a noncontact fashion.

Effects of interfacial Dzyaloshinskii–Moriya interaction on magnetic dynamics

In the “Beyond Moore” era, the information device is expected to exhibit advantages including small sizes, high processing speed, and low power and dissipation. The novel magnetic information device with these advantages is made of heavy metal(HM)/ferromagnet (FM) composite. Owing to the asymmetric structure, the anisotropic exchange coupling named the interfacial Dzyaloshinskii–Moriya interaction (iDMI) is generated at the HM/FM interface. This iDMI influences the magnetic dynamics including ferromagnetic resonance (FMR), spin wave, and the motion of chiral DWs. These magnetic dynamic behaviors are the bases of the functions of novel magnetic information devices. Therefore, the influence of iDMI on the magnetic dynamics has attracted wide attention in recent years. In this topical review, we give a detailed introduction and discussion about recent investigation on the iDMI-relevant magnetic dynamics of the HM/FM bilayer system. This review consists of five sections: (1). the introduction about the background, the basic theory of magnetic dynamics and DMI; (2). the review about the effect of iDMI on the propagation of spin wave. Owing to the iDMI, the dispersion relationship of spin wave is asymmetric. This not only offers a precise method for measuring the iDMI constant, but also gives rise to potential application for novel magnonic devices. (3). the review about the effect of iDMI on the FMR. Unique iDMI-relevant mode was observed in the FMR spectra owing to the nonparallel alignment of magnetic moments. (4). the review about the motion of DWs with chiral structure due to iDMI. The iDMI plays a fundamental role in the high velocity of the chiral DWs. Meanwhile, the iDMI results in the tilting of DW plane, and the mechanism has been widely investigated. The tilting of the DW plane may be depressed by the interlayer exchange coupling. (5). finally, we summarize the review and give an outlook.

Mechanically axially chiral catenanes and noncanonical chiral rotaxanes

Chirality, the property of objects that are distinct from their own mirror image, is important in many scientific areas but particularly chemistry, where the appearance of molecular chirality because of rigid arrangements of atoms in space famously influences a molecule’s biological properties. Less generally appreciated is that two molecular rings with chemically distinct faces combined like links in a chain results in a chiral structure even when the rings are achiral. To date, no enantiopure examples of such mechanically axially chiral catenanes has been reported. We re-examined the symmetry properties of the mechanically axially chiral motif and identified a straightforward route to such molecules from simple building blocks. We also identify that common representations of axially chiral catenanes obscure that a previously overlooked stereogenic unit arises when a ring is threaded onto a dumbbell-shaped molecule to generate a rotaxane. These insights allowed us to demonstrate the first stereoselective syntheses of an axially chiral catenane and a noncanonical axially chiral rotaxane motif. With methods to access these structures in hand, the process of exploring their properties and applications can now begin.

Mechanically axially chiral catenanes and noncanonical chiral rotaxanes

Chirality, the property of objects that are distinct from their own mirror image, is important in many scientific areas but particularly chemistry, where the appearance of molecular chirality because of rigid arrangements of atoms in space famously influences a molecule’s biological properties. Less generally appreciated is that two molecular rings with chemically distinct faces combined like links in a chain results in a chiral structure even when the rings are achiral. To date, no enantiopure examples of such mechanically axially chiral catenanes has been reported. We re-examined the symmetry properties of the mechanically axially chiral motif and identified a straightforward route to such molecules from simple building blocks. We also identify that common representations of axially chiral catenanes obscure that a previously overlooked stereogenic unit arises when a ring is threaded onto a dumbbell-shaped molecule to generate a rotaxane. These insights allowed us to demonstrate the first stereoselective syntheses of an axially chiral catenane and a noncanonical axially chiral rotaxane motif. With methods to access these structures in hand, the process of exploring their properties and applications can now begin.

Mechanically axially chiral catenanes and noncanonical chiral rotaxanes

Chirality, the property of objects that are distinct from their own mirror image, is important in many scientific areas but particularly chemistry, where the appearance of molecular chirality because of rigid arrangements of atoms in space famously influences a molecule’s biological properties. Less generally appreciated is that two molecular rings with chemically distinct faces combined like links in a chain results in a chiral structure even when the rings are achiral. To date, no enantiopure examples of such mechanically axially chiral catenanes has been reported. We re-examined the symmetry properties of the mechanically axially chiral motif and identified a straightforward route to such molecules from simple building blocks. We also identify that common representations of axially chiral catenanes obscure that a previously overlooked stereogenic unit arises when a ring is threaded onto a dumbbell-shaped molecule to generate a rotaxane. These insights allowed us to demonstrate the first stereoselective syntheses of an axially chiral catenane and a noncanonical axially chiral rotaxane motif. With methods to access these structures in hand, the process of exploring their properties and applications can now begin.