Non-Fermi-liquid behavior in cubic phase BaRuO3_{3}: A dynamical mean-field study

Motivated by the recently synthesized cubic phase BaRuO$_{3}$ under high pressure and high temperature, a thorough study has been conducted on its temperature-dependent electronic properties by using the state-of-the-art \textit{ab inito} computing framework of density functional theory combined with dynamical mean-field theory. At ambient condition the cubic phase BaRuO$_{3}$ should be a weakly correlated Hund's metal with local magnetic moment. The spin-spin correlation function and local magnetic susceptibility can be well described by the Curie-Weiss law over a wide temperature range. The calculated low-frequency self-energy functions of Ru-4d states apparently deviate from the behaviors predicted by Landau Fermi-liquid theory. Beyond that, the low-frequency optical conductivity can be fitted to a power-law $\Re\sigma(\omega) \sim \omega^{-0.98}$, which further confirms the Non-Fermi-liquid metallic state.Comment: 6 pages, 4 figure

Fast ground-state cooling of mechanical resonator with time-dependent optical cavities

We propose a feasible scheme to cool down a mechanical resonator (MR) in a three-mirror cavity optomechanical system with controllable external optical drives. Under the Born-Oppenheimer (BO) approximation, the whole dynamics of the mechanical resonator and cavities is reduced to that of a time-dependent harmonic oscillator, whose effective frequency can be controlled through the optical driving fields. The fast cooling of the MR can be realized by controlling the amplitude of the optical drives. Significantly, we further show that the ground-state cooling may be achieved via the three-mirror cavity optomechanical system without the resolved sideband condition.Comment: Some references including our previous works on cooling of mechanical resonators are added, and some typos are corrected in this new version. Comments are welcom

Design Of Ruthenium(ii) Polypyridyl Complexes For Effectively Caging Nitriles And Aromatic Heterocycles

ABSTRACT DESIGN OF RUTHENIUM(II) POLYPYRIDYL COMPLEXES FOR EFFECTIVELY CAGING NITRILES AND AROMATIC HETEROCYCLES by AO LI May 2018 Advisor: Dr. Jeremy Kodanko Major: Chemistry Degree: Doctor of Philosophy Ru(II) polypyridyl complexes have been frequently employed in the caging and photorelease of biologically active compounds. Traditional photocaging groups derived from Ru(II) have been largely based on bi- or tridentate ancillary ligands, and those bearing ancillary ligands with high-denticities are yet to be developed. Exploring Ru(II) polypyridyl complexes possessing ancillary ligands with high-denticities provides insight into the photophysical and photochemical properties of ruthenium complexes, which creates novel prospects in the design of ruthenium complexes applicable towards photoactivated drug delivery and energy conversion.In this thesis, we present a series of Ru(II)-based photocages derived from tetradentate ancillary ligands TPA and cyTPA that have been developed as effective photocaging groups for nitriles and aromatic heterocycles. All complexes exhibit excellent stability in the dark and selectively release the caged nitriles and aromatic heterocycles upon irradiation with light. My findings contribute to showing that Ru(TPA) is appropriate as a photochemical agent to offer precise control over biological activity without undesired toxicity. In addition, the results in this thesis reveal a transtype effect that significantly promotes ligand photodissociation in Ru(II) polypyridyl complexes,where a complex presents a highly mixed 3MCLT/3pp* excited state as the lowest triplet state to achieve an efficient photoinduced ligand exchange. Such an unusual manner offers a clearer understanding of the mechanisms of ligand photodissociation, which can be used to design ruthenium complexes for the applications that require efficient ligand dissociation, such as drug delivery. Furthermore, in order to control CYP activity and to achieve photoactivated CYP inhibition, a series of new Ru(II)-caged CYP inhibitors that effectively liberate CYP inhibitors upon irradiation with low-energy light are described in this thesis. The complexes show strong absorption in the visible range but remain stable in the dark. Photoreleased CYP inhibitors are demonstrated to be capable of undergoing a Type II binding to inactivate CYP activity, and the photo byproducts are non-toxic and well-tolerated by cells. Taken together, this thesis addressed the necessity of the development of Ru(II)-based photocaging groups with high-denticity ancillary ligands for caging nitriles and aromatic heterocycles, and the thesis also established the design and synthesis of Ru(II)-caged CYP inhibitors for controlling CYP activity spatiotemporally with lowenergy ight