473 research outputs found

    Optimal Covariant Measurement of Momentum on a Half Line in Quantum Mechanics

    Full text link
    We cannot perform the projective measurement of a momentum on a half line since it is not an observable. Nevertheless, we would like to obtain some physical information of the momentum on a half line. We define an optimality for measurement as minimizing the variance between an inferred outcome of the measured system before a measuring process and a measurement outcome of the probe system after the measuring process, restricting our attention to the covariant measurement studied by Holevo. Extending the domain of the momentum operator on a half line by introducing a two dimensional Hilbert space to be tensored, we make it self-adjoint and explicitly construct a model Hamiltonian for the measured and probe systems. By taking the partial trace over the newly introduced Hilbert space, the optimal covariant positive operator valued measure (POVM) of a momentum on a half line is reproduced. We physically describe the measuring process to optimally evaluate the momentum of a particle on a half line.Comment: 12 pages, 3 figure

    Star Formation Efficiency in the Central 1 kpc Region of Early-Type Spiral Galaxies

    Get PDF
    It has been reported recently that there are some early-type spiral (Sa--Sab) galaxies having evident star-forming regions which concentrate in their own central 1-kpc. In such central region, is the mechanism of the star formation distinct from that in disks of spiral galaxies? To reveal this, we estimate the star formation efficiency (SFE) in this central 1-kpc star-forming region of some early-type spiral galaxies, taking account of the condition for this 1-kpc region to be self-gravitating. Using two indicators of present star formation rate (Hα\alpha and infrared luminosity), we estimate the SFE to be a few percents. This is equivalent to the observational SFE in the disks of late-type spiral (Sb--) galaxies. This coincidence may support the universality of the mean SFE of spiral galaxies reported in the recent studies. That is, we find no evidence of distinct mechanism of the star formation in the central 1-kpc region of early-type galaxies. Also, we examine the structure of the central star-forming region, and discuss a method for estimating the mass of star-forming regions.Comment: accepted by A

    Observation of a Highly Spin Polarized Topological Surface State in GeBi2_{2}Te4_{4}

    Get PDF
    Spin polarization of a topological surface state for GeBi2_2Te4_4, the newly discovered three-dimensional topological insulator, has been studied by means of the state of the art spin- and angle-resolved photoemission spectroscopy. It has been revealed that the disorder in the crystal has a minor effect on the surface state spin polarization and it exceeds 75% near the Dirac point in the bulk energy gap region (\sim180 meV). This new finding for GeBi2_{2}Te4_{4} promises not only to realize a highly spin polarized surface isolated transport but to add new functionality to its thermoelectric and thermomagnetic properties.Comment: 5 pages, 4 figure

    Internalization Values Of Character Education Towards The Teruna-Daha In The Medi-Median Tradition

    Get PDF
    National culture and character education is a concept of character education in Indonesia, namely through the process of internalization of education based on the principles of religious, social and cultural norms. The medi-median tradition is one of the cleansing ceremonies that returns all elements in Bhuana Agung and Bhuana alit back to its place, which is carried out by Krama desa in the traditional village of Tenganan Pegringsingan, which in this tradition gives deep meaning as an internalization of values that form the character of religious young people.  General objectives and specific objectives to examine and analyze medi-median traditions, related to the internalization of the value of character education. This type of qualitative research used religious theory, internalization theory, value theory, and ethnographic research approaches. Accumulation data used observation method, interview method, library method, data that has been collected is analyzed by interpretative descriptive analysis method, analysis conducted during and after accumulation data, data reduction activities, data presentation, verification to make conclusions. The results presentation technique is presented by the method of presenting the data formally and informally. Research results (1) The medi-median tradition is carried out at Sasih Kapitu, with a series of muhu-muhu ceremonies in the dalem kangin and medi-median in the north to south of the village area, with implementation plans initiated by the medimedian initiator. (2) Internalization of character values through 3 stages, namely the value transformation stage, transaction value stage and transinternalisation stage. (3) internalization of character values towards the teruna-daha in the medi-median tradition, which are: religious values, social values, values. tolerance, discipline value, friendly/communicative value, creative value, aesthetic value, and value of responsibility.</p

    Prediction of Future Land Use and Land Cover (LULC) in Makassar City

    Get PDF
    Migration from rural area to urban area increases urban population. It increases and needs for settlements, leading to conversion of agricultural lands into settlement areas. Inconsistent land use compared with spatial planning causes change in land use. Spatial land use expansion can be monitored and predicted by modeling. NetLogo application is a software integrated with Agent-Based Modeling (ABM), which can be used to predict change of land use with various complex parameters. The present study used population growth as a parameter to predict change of land use of Makassar in 2050 based on 2017 land use classification map as the start of the prediction. The analysis result showed that the biggest change of land use happens to Settlement class which is 594.74 hectares and the smallest is Water Body class which is 8.76 hectares

    Photometric IGM tomography with Subaru/HSC: the large-scale structure of Lyα emitters and IGM transmission in the COSMOS field at z ∼ 5

    Get PDF
    We present a novel technique called “photometric IGM tomography” to map the intergalactic medium (IGM) at z ≃ 4.9 in the COSMOS field. It utilizes deep narrow-band (NB) imaging to photometrically detect faint Lyα forest transmission in background galaxies across the Subaru/Hyper-Suprime Cam (HSC)’s 1.8sq.deg field of view and locate Lyα emitters (LAEs) in the same cosmic volume. Using ultra-deep HSC images and Bayesian spectral energy distribution fitting, we measure the Lyα forest transmission at z ≃ 4.9 along a large number (140) of background galaxies selected from the DEIMOS10k spectroscopic catalogue at 4.98 < z < 5.89 and the SILVERRUSH LAEs at z ≃ 5.7. We photometrically measure the mean Lyα forest transmission and achieve a result consistent with previous measurements based on quasar spectra. We also measure the angular LAE-Lyα forest cross-correlation and Lyα forest auto-correlation functions and place an observational constraint on the large-scale fluctuations of the IGM around LAEs at z ≃ 4.9. Finally, we present the reconstructed 2D tomographic map of the IGM, co-spatial with the large-scale structure of LAEs, at a transverse resolution of 11h−1cMpc across 140h−1cMpc in the COSMOS field at z ≃ 4.9. We discuss the observational requirements and the potential applications of this new technique for understanding the sources of reionization, quasar radiative history, and galaxy-IGM correlations across z ∼ 3 − 6. Our results represent the first proof-of-concept of photometric IGM tomography, offering a new route to examining early galaxy evolution in the context of the large-scale cosmic web from the epoch of reionization to cosmic noon

    Time-optimal CNOT between indirectly coupled qubits in a linear Ising chain

    Full text link
    We give analytical solutions for the time-optimal synthesis of entangling gates between indirectly coupled qubits 1 and 3 in a linear spin chain of three qubits subject to an Ising Hamiltonian interaction with equal coupling JJ plus a local magnetic field acting on the intermediate qubit. The energy available is fixed, but we relax the standard assumption of instantaneous unitary operations acting on single qubits. The time required for performing an entangling gate which is equivalent, modulo local unitary operations, to the CNOT(1,3)\mathrm{CNOT}(1, 3) between the indirectly coupled qubits 1 and 3 is T=3/2J1T=\sqrt{3/2} J^{-1}, i.e. faster than a previous estimate based on a similar Hamiltonian and the assumption of local unitaries with zero time cost. Furthermore, performing a simple Walsh-Hadamard rotation in the Hlibert space of qubit 3 shows that the time-optimal synthesis of the CNOT±(1,3)\mathrm{CNOT}^{\pm}(1, 3) (which acts as the identity when the control qubit 1 is in the state 0\ket{0}, while if the control qubit is in the state 1\ket{1} the target qubit 3 is flipped as ±\ket{\pm}\rightarrow \ket{\mp}) also requires the same time TT.Comment: 9 pages; minor modification
    corecore