Does the Expectation Hypothesis Hold at the Shortest End of the Term Structure?

This paper examines the predictability smile at the shortest end of the term structure. The existence of a predictability smile has been well documented: spreads between long rates and short rates are able to forecast subsequent movements in interest rates well, provided the horizon is three months or less or two years or more. The predictive power of the spread at the shortest maturities, however, has not been adequately investigated. This is a potential shortcoming of the existing literature as a projection of the predictability smile to the shorter maturities is not a guarantee that the expectations hypothesis holds. In Japan, a positive spread between the forward and the spot rates has insufficient predictive power for the future spot rate innovations, while a negative spread has near-perfect predictive ability. Further, we provide evidence that this result is not unique to Japan, as we find this "asymmetric predictability" to be a feature of the very short-term money markets of the U.S., U.K. and Italy.Term Structure, Predictability, Money Market

The Effectiveness of Public Credit Guarantees in the Japanese Loan Market

This paper examines the effectiveness of public credit guarantee programs in not only increasing the availability of loans to small and medium enterprises (SMEs), but in also improving the ex-post performance of borrowing firms. Using a unique panel data set, we identify the effects of a massive credit guarantee program implemented by the Japanese government from 1998-2001. While we do find that the availability of loans increased for program participants, when loans were provided by undercapitalized banks the increased liquidity persisted for only a few years. Further, the ex-post performance of program participants, with the exception of firms with sizable net worth, deteriorated relative to their non-participating counterparts.Credit crunch, Small and Medium Enterprises, Loan guarantees, Matching estimation

Theory of Spin polarized Tunneling in Superconducting Sr2RuO4

A theory of tunneling conductance in ferromagnetic metal/insulator/triplet - supercondcutor junctions is presented for unitary and non-unitary spin triplet pairing states which are promising candidates for the superconducting paring symmetry of Sr2RuO4. As the magnitude of the exchange interaction in the ferromagnetic metal is increased, the conductance for the unitary pairing state below the energy gap is reduced in contrast to the case for the non-unitary pairing state

Electronic Properties of Topological Materials: Optical Excitations in Moebius Conjugated Polymers

Electronic structures and optical excitations in Moebius conjugated polymers are studied theoretically. Periodic and Moebius boundary conditions are applied to the tight binding model of poly(para-phenylene), taking exciton effects into account. We discuss that oligomers with a few structural units are more effective than polymers for observations of effects of discrete wave numbers that are shifted by the change in boundary condition. Next, calculations of optical absorption spectra are reported. Certain components of optical absorption for an electric field perpendicular to the polymer axis mix with absorption spectra for an electric field parallel to the polymer axis. Therefore, the polarization dependences of an electric field of light enable us to detect whether conjugated polymers have the Moebius boundary.Comment: 10 pages, 6 figures, to be published in J. Phys. Soc. Jpn., Vol. 74 No. 2 (February, 2005), Letter sectio

Room-temperature ballistic transport in narrow graphene strips

We investigate electron-phonon couplings, scattering rates, and mean free paths in zigzag-edge graphene strips with widths of the order of 10 nm. Our calculations for these graphene nanostrips show both the expected similarity with single-wall carbon nanotubes (SWNTs) and the suppression of the electron-phonon scattering due to a Dirichlet boundary condition that prohibits one major backscattering channel present in SWNTs. Low-energy acoustic phonon scattering is exponentially small at room temperature due to the large phonon wave vector required for backscattering. We find within our model that the electron-phonon mean free path is proportional to the width of the nanostrip and is approximately 70 $\mu$m for an 11-nm-wide nanostrip.Comment: 5 pages and 5 figure

Tunneling current in triplet f-wave superconductors with horizontal lines of nodes

We calculate the tunneling conductance spectra of a normal-metal/insulator/triplet superconductor using the Blonder-Tinkham-Klapwijk (BTK) formulation. Possible states for the superconductor are considered with horizontal lines of nodes, breaking the time reversal symmetry. These results would be useful to discriminate between pairing states in superonductor Sr$_2$RuO$_4$ and also in UPt$_3$.Comment: 12 pages, 7 figure

Theory of tunneling spectroscopy in superconducting Sr2RuO4

A theory for tunneling spectroscopy in normal metal /insulator/triplet superconductor junction is presented. We assume two kinds of non-unitary triplet superconducting states which are the most promising states for Sr$_{2}$RuO$_{4}$. The calculated conductance spectra showzero-bias peaks as well as gap structures. The existences of residual components in the spectra reflect the non-unitary properties of superconducting states.Comment: 5pages, 4figures(included), to be published in Phys.Rev.B 56, (1997