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We reexamine two-dimensional Lorentzian conformal field theory using the formalism previously developed in a study of sine-square deformation of Euclidean conformal field theory. We construct three types of Virasoro algebra. One of them reproduces the result by Lüscher and Mack, while another type exhibits divergence in the central charge term. The third leads to a continuous spectrum and contains no closed time-like curve in the system.

In this study, we examined consequences of unconventional time development of two-dimensional conformal field theory induced by the L 1 and L −1 operators, employing the formalism previously developed in a study of sine-square deformation. We discovered that the retainment of the Virasoro algebra requires the presence of a cut-off near the fixed points. The introduction of a scale by the cut-off makes it possible to recapture the formula for entanglement entropy in a natural and straightforward manner.

We revisit conformal quantum mechanics (CQM) from the perspective of sine-square deformation (SSD) and the entanglement Hamiltonian. The operators related to SSD and the entanglement Hamiltonian are identified. Thus, the nature of SSD and the entanglement can be discussed in a much simpler CQM setting than higher-dimensional field theories.

In this review, we describe recent progress made in the study of nanoparticles characterized by scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS). Basic principles of STM measurements and single-electron tunneling phenomena through a single NP are summarized. We highlight the results of electrical and photonic properties on NPs studied by STM and STS. Because nanoparticles are single-digit nanometre in diameter, a single-electron transport on individual nanoparticles such as Coulomb blockade and resonant tunneling through discrete energy levels are investigated. Photon-emission from NPs is also introduced based on STM measurements. Novel single-nanoparticle functions such as stochastic blinking and one-write erasing behaviours are presented. This review provides an overview of nanoparticle characterization methods based on STM and STS that include the detailed understanding of the electrical and photonics properties of nanoparticles.

Elaborating on our previous presentation, where the term {\it dipolar quantization} was introduced, we argue here that adopting $L_0-(L_1+L_{-1})/2+{\bar L}_0-({\bar L}_1+{\bar L}_{-1})/2$ as the Hamiltonian instead of $L_0+{\bar L}_0$ yields an infinite circumference limit in two-dimensional conformal field theory. The new Hamiltonian leads to dipolar quantization instead of radial quantization. As a result, the new theory exhibits a continuous and strongly degenerated spectrum in addition to the Virasoro algebra with a continuous index. Its Hilbert space exhibits a different inner product than that obtained in the original theory. The idiosyncrasy of this particular Hamiltonian is its relation to the so-called sine-square deformation, which is found in the study of a certain class of quantum statistical systems. The appearance of the infinite circumference explains why the vacuum states of sine-square deformed systems are coincident with those of the respective closed-boundary systems., 37 pages, 9 figures

素粒子物理学の概要を，3回にわたり平易に解説する。第2回の本稿では，電磁相互作用を媒介する光子などのゲージ粒子を説明する。ゲージ粒子の本質はゲージ対称性にあり，対称性の違いによりゲージ粒子が媒介する相互作用の特質が異なってくる。素粒子物理学で重要になる弱い相互作用及び強い相互作用を媒介するゲージ粒子を説明する。また重要な概念である「対称性の破れ」について説明し，ヒッグス粒子の意義を解説する。

Contamination control has become a high-centered issue for the fabrication yield, performance and reliability of leading-edge ULSI devices. With the progress of sizing down dimensions in higher-density devices, complicated device structures and various novel electronic materials have been introduced, particularly in the latest devices such as CMOS and nonvolatile memory LSIs (Table I). On the other hand, high productivity is a necessity when you consider QTAT (quick turnaround time) and cost-effective flexible ULSI manufacturing lines. Therefore, effective contamination control coupled with adequate protocol has become essential in such production lines. The point of the protocol is minimization of damage caused by impurity metals diffused from these novel electronic materials [1-5].

We have designed tripyridine-thiolato (4, 4 ′ , 4 ″ -tricarboxy-2, 2 ′ : 6 ′ , 2 ″ -terpyridine)ruthenium(II) [complex 1], a novel efficient sensitizing dye for dye sensitized TiO 2 solar cells, based on the DFT MO calculations with PBE0 functional. Complex 1 is a modified BD (black dye: trithiocyanato (4, 4 ′ , 4 ″ -tricarboxy-2, 2 ′ : 6 ′ , 2 ″ -terpyridine)ruthenium(II) complex) molecule where NCS ligands of BD are replaced by C 5 H 4 NS ligands. Molecular and electronic structures of complex 1 have been theoretically characterized. Complex 1 is expected to have the following two advantages over BD, in addition to the advantage of high electron transfer rate from the photoexcited dye to TiO 2 realized in BD: (1) higher electron transfer rate from redox systems to oxidized dyes; (2) higher absorption efficiency to solar spectrum. We propose complex 1 as a novel efficient sensitizing dye which provides the higher efficiency than does BD for dye sensitized solar cells.

The nonperturbative aspects of string theory are explored for non-critical string in two distinct formulations: loop equations and matrix models. The effects corresponding to D-brane in these formulations are especially investigated in detail. It is shown that matrix models can universally yield a definite value of the chemical potential for an instanton while loop equations can not. This implies that string theory may not be nonperturbatively formulated solely in terms of closed strings.

One of the most efficient sensitizing dye called black dye for the dye-sensitized nanocrystalline TiO 2 solar cells have been investigated by the density functional theory study. The microscopic mechanism of electron injection into TiO 2 through the excited state(s) of the dye and electron acceptance from the redox system such as iodide by the oxidized dye molecule has been proposed. The excited electron, which is localized on the terpyridine ligand, can be efficiently injected into TiO 2 . The generated hole, which is localized on the S atom of NCS ligand, can be efficiently filled with the electron from the redox systems. These are the key reason why the sensitization of the black dye is remarkably efficient.

Polysilane oligomer radical anions with up to six Si atoms have been theoretically investigated as model molecules of high polymer polysilane radical anions by ab initio MO theory. According to the calculated results, the polysilane oligomer radical anions can exist as bound anions having a σ-type ground state with an unpaired electron occupying a Si−Si antibonding σ* orbital. They are stabilized with an increase in the Si−Si main chain length both in terms of the boundness of an unpaired electron and bonding strength. The π-type states, on the other hand, exist as excited states for these oligomer radical anions. The calculated results strongly suggest that polysilane radical anions with a π-type ground state are hardly generated regardless of their molecular size and geometry. The Si 3d orbital contributions in the ground and excited states of the polysilane radical anions, such as dπ−dπ conjugations, have also been investigated.

A new formulation of the optimized effective potential (OEP) method is presented. Our OEP method is applicable to the linear combination of atomic orbital (LCAO) calculation for systems which have degenerate orbitals, in contrast to the conventional OEP method. An approximation to our OEP equation for the exchange-correlation (xc) potential, similar to the KLI approximation, is derived.

In order to reproduce the positive isotropic hyperfine coupling constant on the fluorine of C6F6 induced by paramagnetic oxygen in liquid NMR experiment, we calculated six types of geometrical arrangements for the interaction of C6F6 with O2 using the ab initio gaussian program. We also considered the spherical approaches for the bimolecular system where the aromatic plane is taken as the xy plane of a cartesian frame Oxyz. The center of oxygen molecule is referenced by its polar coordinate (l,θ,0), where l and θ denote the intermolecular distance between the center of aromatic plane and that of oxygen, and the angle between the aromatic plane and oxygen center, respectively. The calculations for potential energy surface of C6F6–O2 system were performed using unrestricted Hartree–Fock MO method with 6-31G∗ basis set. We obtained reasonable structures of C6F6–O2 complex (where the bond axis of oxygen molecule is parallel or at right angles to the two fluorine atoms of the C6F6 plane) which reproduce the positive isotropic hyperfine coupling constant on the fluorine of C6F6 in NMR experiment.

Figure 1: Open boundary condition Recently, a very intriguing observation was made regarding the boundary conditions of quantum systems [1]. Consider a system consists of N sites, each of which couples to two nearest sites with an equal strength, except at the ends (Fig. 1). This system with the open boundary condition is, obviously, not uniform in the sense that the system has two singular sites, that are the two endpoints. One may try to lessen the effects from these singularities by modulating the strength of the couplings gradually near the endpoints, in contrast to the open boundary case where the couplings are shut abruptly at the ends. Promoting this line of idea further, the authors of [1] reached the modulation of the coupling such that the coupling between lth and (l + 1)th site = sin ( lπ N ) as depicted in the fig. 2 . They, then, found that the vacuum of the system is identical with that of closed boundary condition (Fig. 3) for certain quantum systems. This modulation is named Sine Square Deformation (of the coupling) after the function appears in the defining equation of the coupling.

We propose a unitary matrix formulation of type IIB matrix model. One-loop effective action of the model exhibits supersymmetry for BPS background in the large N limit.

A time-dependent density-functional theory for systems in periodic external potentials in time is formulated on the assumption of the existence of the Floquet states from the quasienergy viewpoint. Coupling strength integration, which connects a noninteracting system with an interacting system, is introduced by using the time-dependent Hellmann–Feynman theorem. Coupled perturbed time-dependent Kohn–Sham equations are derived from the variational condition to the quasienergy functional with respect to parameters. Explicit expressions for frequency-dependent polarizability and first hyperpolarizability are given by the quasienergy derivative method. Excitation energies and transition moments are defined from poles and residues of frequency-dependent polarizabilities, respectively. In contrast to the previous theory, our formulation has the following three advantages: (1) The time-dependent exchange-correlation potential is defined by the functional derivative of the exchange-correlation quasienergy. (2) The formal expression for frequency-dependent polarizability, which corresponds to the exact sumover-states expression, can be obtained. (3) Explicit expressions for response properties which satisfy the 2n+1 rule can be automatically obtained.

Multiple cluster model (MCM) for investigating surface reactions is formulated. In this model the reaction center, where electron correlation effects often play a key role, is described by an accurate high-level approximation, and bulk effects such as the lattice distortion energy are evaluated using a simple low-level approximation. Therefore, the MCM can properly simulate the potential energy hypersurface of the surface reaction system with a feasible computational cost. Since there exists no fixed atom in the MCM, we can rigorously characterize the stationary point (the minimum energy point or the transition state) on the potential energy hypersurface by vibrational frequency analysis. The MCM can be applied not only to surface systems, but also to various large systems. A detailed comparison of the MCM with the integrated molecular orbital+molecular mechanics (IMOMM), the integrated molecular orbital+molecular orbital (IMOMO), and ONIOM developed by Morokuma and co-workers is also presented. ©1999 John Wiley & Sons, Inc. Int J Quant Chem 71: 403–413, 1999

We derive a long distance effective action for space-time coordinates from a IIB matrix model. It provides us an effective tool to study the structures of space-time. We prove the finiteness of the theory for finite $N$ to all orders of the perturbation theory. Space-time is shown to be inseparable and its dimensionality is dynamically determined. The IIB matrix model contains a mechanism to ensure the vanishing cosmological constant which does not rely on the manifest supersymmetry. We discuss possible mechanisms to obtain realistic dimensionality and gauge groups from the IIB matrix model., Comment: 39 pages, Latex, uses epsf and axodraw

The known BPS dyon black hole solutions of the N=4 heterotic string in four dimensions with a nonzero angular momentum all have naked singularities. We show that it is possible to modify a certain class of these solutions by the addition of massive Kaluza-Klein fields in such a way that the solutions decompactify near the core to five-dimensional black hole solutions with regular event horizons. We argue that the degeneracy of the four-dimensional BPS dyon states is given, for large charges, by the five-dimensional geometric entropy. {copyright} {ital 1997} {ital The American Physical Society}

The hydroxylation mechanism of the H-terminated Si surface in aqueous solutions has been theoretically studied by a quantum chemical approach. OH − ion instead of H 2 O plays a dominant role in the surface hydroxylation, where two different reaction pathways exist. One of them is accompanied with the SiSi back bond cleavage. The high reactivity of the residual surface SiF bonds is also discussed.

We construct a new extreme black hole solution in a toroidally compactified heterotic string theory. The black hole saturates the Bogomol{close_quote}nyi bound, has zero angular momentum, but a nonzero electric dipole moment. It is obtained by starting with a higher-dimensional rotating charged black hole, and compactifying one direction in the plane of rotation. {copyright} {ital 1996 The American Physical Society.}

We suggest that the Hermitian matrix models with resonant tunneling may exhibit novel criticality. Some features of the proposed criticality are explored. In particular, we argue that the new critical point is connected with the first-order transition., 11 pages, 6 figures. v2: References added

A novel three-component chemically amplified positive tone resist system for EB lithography composed of a novolak resin, an acid generator, and a newly synthesized dissolution inhibitor, is investigated. Four 1-(3H)-isobenzofuranone derivatives containing a tert-butoxycarbonyl (t-Boc) group and a lactone ring have been synthesized as dissolution inhibitors. The t-Boc group of these dissolution inhibitors was effectively decomposed by an acid catalyzed thermal reaction. In addition to this decomposition, the lactone ring of the decomposed product was spontaneously cleft in an aqueous base to generate carboxylic acid. Among these synthesized substances, only the t-Boc derivative of o-cresolphtalein showed an excellent solubility in 1-acetoxy-2-ethoxyethane

The potential energy surface of the vinyl chloride radical anion, which is the simplest chlorine-containing hydrocarbon anion having a CC π system, has been studied by ab initio molecular orbital theory. The calculated results indicate that the initial 2 Π state is rapidly changed to the repulsive 2 Σ state by a CCl out-of-plane deformation during CCl dissociation. While no metastable 2 Π state is found on the potential energy surface, the same kind of planar metastable weak complex is found on the minimum energy path as in the case of the methyl chloride radical anion. The differences and similarities between the CCl dissociation minimum energy paths of the vinyl chloride and methyl chloride radical anions are also discussed.

Quantum chemical calculation is applied to investigate the reaction mechanism of sulfonyl acid generator and the transparency of the resist material. We have found that electron absorbed dimethylsulfone can be easily decomposed by relatively low energy (2.95Kcal/mol), reaching to the decomposed status of methyl radical and CH3SO2 (methyl sulfonyl anion). This was thought to bean initial step in the electron acid generation reaction of the sulfonyl compounds. The total molecular energy of dimethyl sulfone anion was found to be higher than that of the neutral dimethylsulfone. On the other hand, sulfone derivatives with electron-withdrawing groups, such as methyl sulfonyl acetonitrile, usually have higher energy (about 41kcal/mol) than those for their anion. This suggests that the electron withdrawing groups enhance the electron affinity of the sulfone compounds, which are also considered to increase the efficiency of acid generation. Additionally, another quantum chemical study was carried out in order to improve transparency of the aromatic species in resist for ArF excimer laser. Using configuration interaction (CI) methods of molecular orbital theory, the substituent effects of UV absorption in the aromatic compounds were investigated. As a result significant red sifts in λmax were observed in the conjugated romatic rings, which increases the transparency at 193nm wavelength region.

Core-shell Au nanoparticles were synthesized for chemical reaction under mild liquid phase condition. The nanoparticles film was fabricated on a glass substrate for surface plasmon polariton waveguide. The nanoparticle piled up on the substrate made a smooth surface. A waveguide was easily fabricated by the lift-off method and the patterned trench filled method.

The reaction of trimethylaluminium (Al(CH 3 ) 3 , TMA) with H 2 has been investigated using ab initio molecular orbital calculations. It has been shown that the activation energy of the reaction, TMA + H 2 → AlH(CH 3 ) 2 + CH 4 , is about 1/2 of the dissociation energy of radical decomposition, TMA → Al(CH 3 ) 2 + CH 3 . This means that TMA decomposition under conditions where collisions between TMA and H 2 are sufficiently frequent is dominated by hydrogenolysis. This explains the experimental result that the decomposition temperature of TMA becomes lower with increasing H 2 pressure.

Disilane, silylgermane, and digermane radical anions have been studied by ab initio molecular orbital theory, using the unified level of basis set as prototypes of polymer anions with Si and Ge backbones. These prototype anions have the same kind of minimium geometry (C 2h or C 2h -like symmetry) with an unpaired electron occupying the Si-Si, Si-Ge, or Ge-Ge σ * antibonding orbital with a large Si or Ge s diffuse orbital contribution. Littke Si 3d or Ge 4d orbital participation is found for these anions

Substituent effects on the silane radical anion have been studied by ab initio molecular orbital theory. According to the calculated results, the second-row substituents tend to stabilize the silane anion more than do the first-row substituents. It has also been found that the stability of an unpaired electron is increased with an increase in the electron-withdrawing effect of the substituents, at least as far as the same-row substituents are concerned. The difference between the first- and second-row substituent effects can be qualitatively explained both by the orbital interaction based on perturbation theory and by the difference in the diffuseness of the atomic basis functions between the first- and second-row atoms

The electronic structures of layered-perovskite oxides Sr n +1 V n O 3 n +1 ( n =1, 2, 3) have been analyzed through ab initio molecular-orbital calculations for VO 6 clusters, using the Hartree-Fock method followed by Moller-Plesset perturbation and configuration-interaction corrections. Comparisons of the electronic states have been made among VO 6 , CuO 6 and CuO 4 clusters to study the possibility of realizing vanadate superconductors on the analogy of the high- T c cuprate superconductors. Hole- and electron-doped states have also been investigated as well as the undoped state. We thus clarify a number of similarities and differences between the vanadates and the cuprates. It is also suggested that some of these differences may prevent the layered vanadium oxides from becoming high- T c superconductors.

We derived an asymptotic formula for q-6j symbol. This is a generalization of the former work by Ponzano and Regge. Studying the q-deformed su(2) spin network as a 3-dimensional quantum gravity model, we show that the Turaev-Viro invariant defines naturally regularized path-integral a la Ponzano-Regge in the semi-classical continuum limit. We find a term which should be related to the cosmological constant term in 3-dimensional gravity. The contribution from the cosmological term is effectively included in the pathintegral from the invariant, and the cosmological constant is found to be 4π 2 /k 2 +O(k −4 ), where q 2k =1. We point out also that the duality matrices of the su(2) WZW model may be identified as the Turaev-Viro invariant evaluated on a certain 3-manifold

The thermal decomposition process of tertiarybutylphosphine (C(CH3)3PH2, TBP) has been investigated by ab initio molecular orbital calculations. It has been shown that the radical process, TBP→C(CH3)3+PH2, is the energetically most favorable process among the processes which are effective for metalorganic chemical vapor deposition. The calculated dissociation energy of TBP was smaller than that of PH3. This result explains the experimental results that the growth temperature is lower for the use of a TBP source than for a PH3 source.

We present a prescription to obtain an arbitrary ( q , p ) critical point from two-matrix models with asymmetric potentials of 2( p −1)th order. We illustrate it with the examples of the (3,5) and (5,6) points.

ArF lithography sometimes generates the haze defects on the phot omask substrate, resulting in serious yield deterioration in ULSI production. In order to solve this problem, experimental and theoretical studies have been carried out on the generated haze defects. In characterizing the haze defects, the composition and chemical structure of the haze defects were analyzed by focusing on 1.0 x 0.3µm sizes defects using Raman, ToF-SIMS and AES spectroscopy with their highest spatial and mass resolution level. To confirm the experimental analyses, theoretical ab initio molecular orbital calculations were carried out on the model compounds of the generated haze defects. These experimental and theoretical studies indicate that the haze defects on quartz surface consist of (NH 4 ) 2 SO 4 and that those on half-tone (HT) film surface, on the other hand, consist of (MoO 3 ) x (SO 4 ) y (NH 4 ) z complex including Mo from HT film material. In the latter case, NH 4 ion was observed only in surface region of the haze defects. Based on these results, we have proposed a novel model of haze generation mechanism on quartz and HT film surfaces of photomask substrate. Keywords: haze, Mo, molybdenum oxide, sulfate, half-tone, ammonium-sulfate, Raman, ToF-SIMS, AES, low-energy-SEM, ab initio MO

The two-matrix model with the sixth order potential is investigated. We construct Douglas' Q and P operators from the matrix model by directly taking the continuum limit of the corresponding matrix operators, and show that the (4,5) and (3,8) minimal models are realized at the critical points.

Disilane radical anion has been investigated as a prototype of polysilane anions by ab initio molecular orbital theory. Disilane in a D 3d structure is distorted to a C 2h structure by receiving an electron. In the C 2h minimum geometry, disilane anion has a 2 B u electronic structure with an unpaired electron occupying a Si-Si antibonding σ * orbital (b u ) with a large Si s diffuse orbital contribution. It is found to be a kinetically bound anion. No Si 3d orbital participation is found in this anion. These results suggest that more stable polysilane anions also have the same kind of molecular and electronic structures.

Sine-square deformation, a recently found modulation of the coupling strength in certain statistical models, is discussed in the context of two-dimensional conformal field theories, with particular attention to open/closed string duality. This deformation is shown to be non-trivial and leads to a divergence in the worldsheet metric. The structure of the vacua of the deformed theory is also investigated. The approach advocated here may provide an understanding of string duality through the worldsheet dynamics., Comment: 15 pages, 4 figures

We present a new fermionic solution of the supersymmetric matrix model. The solution satisfies the commutation and anticommutation relations for noncommutative superspace. Therefore the solution can be considered as an implementation of noncommutative superspace on the matrix model., 9 pages, no figure, version submitted to Phys. Lett. B

The potential energy surface of the methyl chloride radical anion has been studied by ab initio molecular orbital theory. The following calculated results are obtained, different from the reported C-Cl dissociation potential curves: (1) A shallow least energy point (stationary point) is found within C 3υ symmetry in cases where dynamical correlation effects are taken into consideration

We review our proposal for a constructive definition of superstring, type IIB matrix model. The IIB matrix model is a manifestly covariant model for space-time and matter which possesses N=2 supersymmetry in ten dimensions. We refine our arguments to reproduce string perturbation theory based on the loop equations. We emphasize that the space-time is dynamically determined from the eigenvalue distributions of the matrices. We also explain how matter, gauge fields and gravitation appear as fluctuations around dynamically determined space-time., 37 pages, LaTex with PTPTex.sty, 2 epsf figures. Proceedings of the 13th Nishinomiya Yukawa Memorial Symposium (November, 1998)

We show that twisted reduced models can be interpreted as noncommutative Yang-Mills theory. Based upon this correspondence, we obtain noncommutative Yang-Mills theory with D-brane backgrounds in IIB matrix model. We propose that IIB matrix model with D-brane backgrounds serve as a concrete definition of noncommutative Yang-Mills. We investigate D-instanton solutions as local excitations on D3-branes. When instantons overlap, their interaction can be well described in gauge theory and AdS/CFT correspondence. We show that IIB matrix model gives us the consistent potential with IIB supergravity when they are well separated., Comment: 21pages, LaTeX, no figures, typos corrected

We investigate the CGHS model through numerical calculation. The behavior of the mass function, which we introduced in our previous work as a ``local mass'', is examined. We found that the mass function takes negative values, which means that the amount of Hawking radiation becomes greater than the initial mass of the black hole as in the case of the RST model.