The structural and electrical properties of an electron-beam (EB)-irradiated C60 film have been examined at room temperature, using in situ infrared (IR) spectroscopy and ex situ four-probe measurements. IR results show that the irradiated film is neither graphite nor carbon nanotube-like but a peanut-shaped C60 polymer. Current–voltage curve shows that the polymer exhibits a metallic property with a drastically reduced resistivity of 7 Ω cm in comparison with 108–1014 Ω cm for solid C60. This indicates the possibility of applying C60 molecules in EB nanofabrication processes and large potential for developing carbon-based nanodevices.

Einstein first applied Riemannian geometry to develop the general theory of relativity almost one hundred years ago and succeeded in understanding astronomical-scale phenomena such as the straining of time-space by a gravitational field. Whether or not Riemannian space affects the electronic properties of condensed matters on a much smaller scale is of great interest. Although Riemannian geometry has been applied to quantum mechanics since the 1950s, nobody has yet answered this question, because the electronic properties of materials with Riemannian geometry have not been examined experimentally. We report here the first observation of Riemannian geometrical effects on the electronic properties of materials such as Tomononaga-Luttinger liquids, which were previously theoretically predicted by our group. We present in situ high-resolution ultraviolet photoemission spectra of a one-dimensional metallic C60 polymer with an uneven periodic peanut-shaped structure.

We demonstrate the effects of geometric perturbation on the Tomonaga-Luttinger liquid (TLL) states in a long, thin, hollow cylinder whose radius varies periodically. The variation in the surface curvature inherent to the system gives rise to a significant increase in the power-law exponent of the single-particle density of states. The increase in the TLL exponent is caused by a curvature-induced potential that attracts low-energy electrons to region that has large curvature. PACS numbers: 73.21.Hb, 71.10.Pm, 03.65.Ge Studying the quantum mechanics of a particle confined to curved surfaces has been a problem for more than fifty years. The difficulty arises from operator-ordering ambiguities [1], which permit multiple consistent quantizations for a curved system. The conventional method used to resolve the ambiguities is the confining-potential approach [2,3]. In this approach, the motion of a particle on a curved surface (or, more generally, a curved space) is regarded as being confined by a strong force acting normal to the surface. Because of the confinement, quantum excitation energies in the normal direction are raised far beyond those in the tangential direction. Hence, we can safely ignore the particle motion normal to the surface, which leads to an effective Hamiltonian for propagation along the curved surface with no ambiguity.It is well known that the effective Hamiltonian involves an effective scalar potential whose magnitude depends on the local surface curvature [2,3,4,5]. As a result, quantum particles confined to a thin, curved layer behave differently from those on a flat plane, even in the absence of any external field (except for the confining force). Such curvature effects have gained renewed attention in the last decade, mainly because of the technological progress that has enabled the fabrication of low-dimensional nanostructures with complex geometry [6,7,8,9,10,11,12,13,14]. From the theoretical perspective, many intriguing phenomena pertinent to electronic states [15,16,17,18,19,20,21,22], electron diffusion [23], and electron transport [24,25,26,27] have been suggested. In particular, the correlation between surface curvature and spin-orbit interaction [28,29] as well as with the external magnetic field [30,31,32] has been recently considered as a fascinating subject.Most of the previous works focused on noninteracting electron systems, though few have focused on interacting electrons [33] and their collective excitations. However, in a low-dimensional system, Coulombic interactions may drastically change the quantum nature of the system. Particularly noteworthy are one-dimensional systems, where the Fermi-liquid theory breaks down so that the system is in a Tomonaga-Luttinger liquid (TLL) state [34]. In a TLL state, many physical quantities exhibit a power-law dependence stemming from the absence of single-particle excitations near the Fermi energy; this situation naturally raises the question as to how geometric perturbation affects the TLL behaviors of quasi onedimensional curved sys...

Columnar liquid crystals composed of a giant macrocyclic mesogen were prepared. The giant macrocyclic mesogen has a square hollow with a 2.5 nm diagonal, which was bounded by diindolo[3,2-b:2',3'-h]carbazole (diindolocarbazole) moieties as the edges and bis(salicylidene)-o-phenylenediamine (salphen) moieties as the corners. The shape and size of the macrocycle were directly observed by scanning tunneling microscopy (STM). Each side of the bright square in the STM image corresponds to a diindolocarbazole moiety, and the length of the sides was consistent with the result of the single crystal analysis of diindolocarbazole. Finally, we successfully obtained a giant macrocycle with long and branched side chains, which exhibited a rectangular columnar LC phase over a wide temperature range. To the best of our knowledge, it contained the largest discrete inner space of any thermotropic columnar liquid crystal composed of macrocyclic mesogens.

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