Kinetics of liquids and glasses is discussed from the view point of elementary excitation in energy landscape, based mainly on the results of computer simulation. We present a new phenomenological model to predict glassy dynamics. We then focus on the action of atomic bond being cut or formed, which changes the local topology of atomic connectivity in liquids. The collectivity of topological change is directly connected to the local potential energy landscape.
We review the recent theoretical development in cold Fermi gas physics, showing several key experiments. In particular, we pick up the BCS-BEC crossover theories, called NSR, TMA, ETMA, as well as SCTMA. We also present a promising application of this atomic gas system to the study of the low-density region of neutron-star interior.
We describe our current efforts to investigate coherent coupling between surface acoustic waves (SAW) and electromagnetic waves in both optical and microwave regimes. We develop a hybrid quantum system consisting of a microwave resonator, a superconducting qubit, and a SAWresonator. The coherent coupling between the circuit components enables us to measure the SAW amplitude near the quantum level. We also describe a cavity optomechanical system formed with a SAW resonator inserted inside an optical cavity. The system provides a possibility to build a coherent interface between the microwave and optical photon at the single-photon level. It is an important building block for the construction of quantum information networks.
In this article, I discuss solvable spin chain models which exhibit extensive entanglement entropy scaling as a square root or a linear of the volume. They provide counterexamples to a belief that the area law for the entanglement entropy of the ground state can be violated at most logarithmically. I also briefly comment on their meaning in elementary particle physics.
Precise time-resolution studies of early-stage photoinduced dynamics are essential to clarify the mechanism of photofunctionality in solid-state materials. A time-resolved electron diffraction technique using sub-picosecond electron pulses was recently developed to measure the diffraction patterns of the photoinduced transient state. In the present study, the abovementioned time-resolved optical and diffraction measurements were analyzed to create a molecular movie that can be directly viewed to better understand photoinduced dynamics in molecular conductors.