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Virtual re-creations of real-world places are attractive and becoming more popular. Attractiveness of re-created place is commonly determined by the degree of visual similarity to the original places. Even if the re-creation has poor similarity to the original, there are cases in which people recognize and allow the re-creation to have similarity as the same entity. However, the mechanisms and factors behind this contradiction have not yet been studied. This is the first study focusing on the activity and meaningofpeoplewhentheyfeelsamenesstoare-createdplace. Thispaper investigates the concept of place sameness, which is defined as the degree of similarity between an original and a virtual re-creation that represents the original place. Further, the factors of place sameness are explored using a classroom re-creation task with virtual reality (VR) technology. The participants were instructed to recreate two classrooms within virtual environmentsusingvirtualfixtures. Asresults, thedisplaydevicesinRoom B, the student desks in Room A at the memory index, display devices in RoomA,andstudentdesksandothersinRoomBattheaveragedistancehad moderate or large correlations with the place sameness index. The results suggest that the reproducibility of the number of objects related to activities in a place, and the inaccuracy of the positions of objects are factors of place sameness. Our own interpretation of the uncanny valley effect of a place was also partially observed. The main contributions of this study are the proposal of the concept of place sameness as a new perspective for virtual re-creation research and the finding of promising factors for that., Comment: Submitted to IEICE TRANSACTIONS on Information and Systems

Spin-density-functional theory of quantum point contacts (QPCs) reveals the formation of a local moment with a net of one electron spin in the vicinity of the point contact - supporting the recent report of a Kondo effect in a QPC. The hybridization of the local moment to the leads decreases as the QPC becomes longer, while the onsite Coulomb-interaction energy remains almost constant., Comment: 10 pages, 3 figures, accepted for publication in Physical Review Letters

Experiments on quantum point contacts have highlighted an anomalous conductance plateau at $0.7 (2e^2/h)$, with features suggestive of the Kondo effect. Here we present an Anderson model for transport through a point contact which we analyze in the Kondo limit. Hybridization to the band increases abruptly with energy but decreases with valence, so that the background conductance and the Kondo temperature $T_K$ are dominated by different valence transitions. This accounts for the high residual conductance above $T_K$. A spin-polarized current is predicted for Zeeman splitting $g^* \mu_B B > k_B T_K,k_BT$., Comment: 4 pages

We investigate the ground-state energy and spin of disordered quantum dots using spin-density-functional theory. Fluctuations of addition energies (Coulomb-blockade peak spacings) do not scale with average addition energy but remain proportional to level spacing. With increasing interaction strength, the even-odd alternation of addition energies disappears, and the probability of non-minimal spin increases, but never exceeds 50%. Within a two-orbital model, we show that the off-diagonal Coulomb matrix elements help stabilize a ground state of minimal spin., Comment: 10 pages, 2 figures

For unpolarized electrons in a clean quantum wire, density functional theory reveals a thermally activated suppression of conductance. The activation temperature T_A grows slowly (roughly quadratically) with gate voltage due to pinning of the band edge at the chemical potential. Similar results were obtained experimentally by Kristensen et al. [Phys. Rev. B62, 10950 (2000)] for the temperature dependence of the anomalous conductance plateau near 0.7 (2e^2/h) in a quantum point contact., Comment: 9 pages, 2 figures

Using spin-density-functional theory, we study the electronic states of a two-dimensional parabolic quantum dot with up to N=58 electrons. We observe a shell structure for the filling of the dot with electrons. Hund's rule determines the spin configuration of the ground state, but only up to 22 electrons. At specific N, the ground state is degenerate, and a small elliptical deformation of the external potential induces a rotational charge-density-wave (CDW) state. Previously identified spin-density-wave (SDW) states are shown to be artifacts of broken spin symmetry in density-functional theory., Comment: 10 pages, 3 figures