@article{kim_vetter_yan_yang_wang_sun_yang_comstock_li_zhou_et al._2023, title={Chiral-phonon-activated spin Seebeck effect}, volume={2}, ISSN={["1476-4660"]}, url={http://dx.doi.org/10.1038/s41563-023-01473-9}, DOI={10.1038/s41563-023-01473-9}, abstractNote={Utilization of the interaction between spin and heat currents is the central focus of the field of spin caloritronics. Chiral phonons possessing angular momentum arising from the broken symmetry of a non-magnetic material create the potential for generating spin currents at room temperature in response to a thermal gradient, precluding the need for a ferromagnetic contact. Here we show the observation of spin currents generated by chiral phonons in a two-dimensional layered hybrid organic-inorganic perovskite implanted with chiral cations when subjected to a thermal gradient. The generated spin current shows a strong dependence on the chirality of the film and external magnetic fields, of which the coefficient is orders of magnitude larger than that produced by the reported spin Seebeck effect. Our findings indicate the potential of chiral phonons for spin caloritronic applications and offer a new route towards spin generation in the absence of magnetic materials.}, journal={NATURE MATERIALS}, publisher={Springer Science and Business Media LLC}, author={Kim, Kyunghoon and Vetter, Eric and Yan, Liang and Yang, Cong and Wang, Ziqi and Sun, Rui and Yang, Yu and Comstock, Andrew H. and Li, Xiao and Zhou, Jun and et al.}, year={2023}, month={Feb} }
 @article{yang_raza_li_liu_2023, title={Thermal Transport in Poly(p-phenylene): Anomalous Dimensionality Dependence and Role of & pi;-& pi; Stacking}, volume={7}, ISSN={["1520-5207"]}, url={http://dx.doi.org/10.1021/acs.jpcb.3c02947}, DOI={10.1021/acs.jpcb.3c02947}, abstractNote={For heat conduction along polymer chains, a decrease in the axial thermal conductivity often occurs when the polymer structure changes from one-dimensional (1D) to three-dimensional (3D). For example, a single extended aliphatic chain (e.g., polyethylene or poly(dimethylsiloxane)) usually has a higher axial thermal conductivity than its double-chain or crystal counterparts because coupling between chains induces strong interchain anharmonic scatterings. Intuitively, for chains with an aromatic backbone, the even stronger π-π stacking, once formed between chains, should enhance thermal transport across chains and suppress the thermal conductivity along the chains. However, we show that this trend is the opposite in poly(p-phenylene) (PPP), a typical chain with an aromatic backbone. Using molecular dynamics simulations, we found that the axial thermal conductivity of PPP chains shows an anomalous dimensionality dependence where the thermal conductivity of double-chain and 3D crystal structures is higher than that of a 1D single chain. We analyzed the probability distribution of dihedral angles and found that π-π stacking between phenyl rings restricts the free rotation of phenyl rings and forms a long-range order along the chain, thus enhancing thermal transport along the chain direction. Though possessing a stronger bonding strength and stabilizing the multiple-chain structure, π-π stacking does not lead to a higher interchain thermal conductance between phenyl rings compared with that between aliphatic chains. Our simulation results on the effects of π-π stacking provide insights to engineer thermal transport in polymers at the molecular level.}, number={30}, journal={JOURNAL OF PHYSICAL CHEMISTRY B}, publisher={American Chemical Society (ACS)}, author={Yang, Cong and Raza, Saqlain and Li, Xiaobo and Liu, Jun}, year={2023}, month={Jul} }
 @article{negi_rodriguez_zhang_comstock_yang_sun_jiang_kumah_hu_liu_2023, title={Thickness-Dependent Thermal Conductivity and Phonon Mean Free Path Distribution in Single-Crystalline Barium Titanate}, volume={4}, ISSN={["2198-3844"]}, url={https://doi.org/10.1002/advs.202301273}, DOI={10.1002/advs.202301273}, abstractNote={Abstract}, journal={ADVANCED SCIENCE}, author={Negi, Ankit and Rodriguez, Alejandro and Zhang, Xuanyi and Comstock, Andrew H. H. and Yang, Cong and Sun, Dali and Jiang, Xiaoning and Kumah, Divine and Hu, Ming and Liu, Jun}, year={2023}, month={Apr} }