Implementation of a quantum controlled-SWAP gate with photonic circuits

Quantum information science addresses how the processing and transmission of information are affected by uniquely quantum mechanical phenomena. Combination of two-qubit gates has been used to realize quantum circuits, however, scalability is becoming a critical problem. The use of three-qubit gates may simplify the structure of quantum circuits dramatically. Among them, the controlled-SWAP (Fredkin) gates are essential since they can be directly applied to important protocols, e.g., error correction, fingerprinting, and optimal cloning. Here we report a realization of the Fredkin gate for photonic qubits. We achieve a fidelity of 0.85 in the computational basis and an output state fidelity of 0.81 for a 3-photon Greenberger-Horne-Zeilinger state. The estimated process fidelity of 0.77 indicates that our Fredkin gate can be applied to various quantum tasks.Comment: 9 pages, 4 figures, Sci. Rep. 7, 45353 (2017

Modelling self-interacting dark matter substructures I: Calibration with N-body simulations of a Milky-Way-sized halo and its satellite

We study evolution of single subhaloes with their masses of $\sim10^9 M_\odot$ in a Milky-Way-sized host halo for self-interacting dark matter (SIDM) models. We perform dark-matter-only N-body simulations of dynamical evolution of individual subhaloes orbiting its host by varying self-scattering cross sections (including a velocity-dependent scenario), subhalo orbits, and internal properties of the subhalo. We calibrate a gravothermal fluid model to predict time evolution in spherical mass density profiles of isolated SIDM haloes with the simulations. We find that tidal effects of SIDM subhaloes can be described with a framework developed for the case of collision-less cold dark matter (CDM), but a shorter typical time scale for the mass loss due to tidal stripping is required to explain our SIDM simulation results. As long as the cross section is less than $\sim10\, \mathrm{cm}^2/\mathrm{g}$ and initial states of subhaloes are set within a $2\sigma$-level scatter at redshifts of $\sim2$ predicted by the standard $\Lambda$CDM cosmology, our simulations do not exhibit a prominent feature of gravothermal collapse in the subhalo central density for 10 Gyr. We develop a semi-analytic model of SIDM subhaloes in a time-evolving density core of the host with tidal stripping and self-scattering ram pressure effects. Our semi-analytic approach provides a simple, efficient and physically-intuitive prediction of SIDM subhaloes, but further improvements are needed to account for baryonic effects in the host and the gravothermal instability accelerated by tidal stripping effects.Comment: 19 pages, 12 figures, 1 table. Accepted for publication in MNRAS. Note that results in the previous manuscript (v1) were affected by a bug in our SIDM implementation. We fixed the bug and updated all results accordingl

The Relationship between the Equivalence Scale and the Inequality Index and Its Impact on the Measurement of Income Inequality

The paper discusses the ∪-shaped relationship between the equivalence scale n^ε and the Gini index instead of considering the equivalence scale’s relationship to the generalised entropy measures, which was studied by Coulter, et al. (1992). An end-point condition is given for the ∪-shaped relationship, which corresponds to a condition for that of the generalised entropy measures. Additionally, using a mixture of log-normal distributions approach, five factors are shown to be required for a convex relationship between size elasticity and the Gini index. Empirically, income distributions satisfy those factors. Thus, the end-point condition essentially determines the shape of the relationship

コウクウガン ノ メンエキ リョウホウ : キソ カラ リンショウ エ : レンサ キュウキン Toll-like receptor ジュジョウ サイボウ

OK-432, a penicillin-killed and lyophilized preparation of a low-virulence strain (Su) of Streptococcus pyogenes (group A), is successfully used as an immunotherapeutic agent in many types of malignancies including head and neck cancer. Recently, we succeeded in isolating the effective molecule (lipoteichoic acid-related molecule OK-PSA) by affinity chromatography of a butanol extract of OK-432 on CNBr-activated sepharose 4B bound TS-2 monoclonal antibody that neutralizes interferon-γ-inducing activity of OK-432. In this review, we described the findings regarding the effect of the OK-432 and OK-PSA in enhancing anti-tumor immunity and the molecular mechanism. Our in vitro and in vivo study demonstrated that OK-PSA induces Th1-type cytokines in human as well as in mice, and elicits anti-tumor effect in tumor-bearing mice. Furthermore, our data indicated that the signaling mediated by Toll-like receptor (TLR) 4/MD-2 was involved in regulating OK-432/OK-PSA-induced anti-tumor immunity. It is suggested that OK-PSA is most responsible molecule for the antitumor effect of OK-432, that TLR4 and MD-2 are certain molecular targets for OK-432 as well as OK-PSA, and that expression of these genes may be useful marker to discriminate between responder and nonresponder to OK-432-based immunotherapy. In addition, OK-432/OK-PSA induced tumor-antigen specific cytotoxic T cells via the maturation of dendritic cells (DCs) which are professional antigenpresenting cells. It has been strongly suggested the possibility that OK-432/OK-PSA may be a useful adjuvant for DC therapy

The Relationship between the Equivalence Scale and the Inequality Index and Its Impact on the Measurement of Income Inequality

The paper discusses the ∪-shaped relationship between the equivalence scale n^ε and the Gini index instead of considering the equivalence scale’s relationship to the generalised entropy measures, which was studied by Coulter, et al. (1992). An end-point condition is given for the ∪-shaped relationship, which corresponds to a condition for that of the generalised entropy measures. Additionally, using a mixture of log-normal distributions approach, five factors are shown to be required for a convex relationship between size elasticity and the Gini index. Empirically, income distributions satisfy those factors. Thus, the end-point condition essentially determines the shape of the relationship

Unitary Matrix Models with a topological term and discrete time Toda equation

We study the full unitary matrix models. Introducing a new term $l log U$, l plays the role of the discrete time. On the other hand, the full unitary matrix model contains a topological term. In the continuous limit it gives rise to a phase transition at $\theta=\pi$. The ground state is characterize by the discrete time l. The discrete time l plays like the instanton number.Comment: 14 pages, LaTeX, 1 eps figur

The Neurophysiological Implications of an Atypical Slow Negative Potential in Short Interval CNV Paradigm

We recorded a slow negative potential from Cz (10/20 method) in 49 healthy students (12 male, 37 female, mean age 19.1) by a short interstumulus interval CNV paradigm. The interstimulus interval was 2 or 3 seconds, the warning stimulus presented at random or regular interval at 0.2 Hz. An atypical negative variation with two separated negative peaks was recorded in 26.0-30.6% trials regardless of interstimulus interval or modality of warning stimulus presentation, while a typical CNV was recorded in 32.0-59.2% of trials. No apparent negative variation was recorded in 14.3-18.4% in 2 seconds interstimulus interval, and 28-38% in 3 seconds interstimulus interval, showing that 2 seconds interval is better to get stable CNV recording than 3 seconds interval. The first negative wave of the atypical negative variation was 692-799msec in duration, but frequently prolonged to 1000msec or more in 3 seconds interval. It usually had negative peak around 900-1100msec, but sometimes around 1500msec. This features are different from any reported negative components of CNV. The second negative wave began 800-1200msec before second stimulus, and had its peak just before second stimulus, showing common features with readiness potential. The appearance of CNV was unsatble in the students in which the atypical negative variation was recorded in regular, 2 seconds intersitimulus interval, and the amplitude of slow vertex response and pattern reversal visual evoked potential was lower in thses students than in the students in which a typical CNV was recorded more than 3 times in total 4 times of trials. These findings indicate that the atypical variation observed in this study is due to a lowered arousal level or cortical neuronal activity, rather than a separated appearance of different components of CNV.CNVの記録条件を検討する目的で、健康若年成人49名（男12、女37）を対象にS(1)-S(2)+Rパラダイムを用いてCNVを記録した。S(1)-S(2)間隔2秒のほうが3秒よりも安定してCNVが記録されたが、刺激間隔とは無関係に26～30％の試行で二峰性の陰性変動をもつ非定型な緩電位が記録された。この緩電位は同一被検者でも出現性が一貫せず、個体差よりも被検者の状態に依存していた。二峰性陰性波のうち、後期成分は準備電位に対応するものと思われたが、前期成分はS(1)後900～1100msecにピークをもつ陰性波で、これまで報告されたCNVの要素波とは対応しなかった。また、この非定型CNVを示す被検者ではCNV出現が不安定で、SVRおよびパターンVEPの振幅が低い傾向があり、試行時の被検者の覚醒水準低下よるものではないかと考えられた

Molecular dynamics of C-peptide of ribonuclease A studied by replica-exchange Monte Carlo method and diffusion theory

Generalized-ensemble algorithm and diffusion theory have been combined in order to compute the dynamical properties monitored by nuclear magnetic resonance experiments from efficient and reliable evaluation of statistical averages. Replica-exchange Monte Carlo simulations have been performed with a C-peptide analogue of ribonuclease A, and Smoluchowski diffusion equations have been applied. A fairly good agreement between the calculated and measured $^1$H-NOESY NMR cross peaks has been obtained. The combination of these advanced and continuously improving statistical tools allows the calculation of a wide variety of dynamical properties routinely obtained by experiments.Comment: 17 pages, 5 figures, (LaTeX); Chemical Physics Letters, in pres