11345528
Topologization of electron liquids with Chern-Simons theory and quantum computation
A semiconductor integrated circuit is provided in which a space for accommodating a light emitting element driver circuit or a current detector circuit for detecting a current from a light receiving element can be reduced even if the number of channels connecting between a plurality of devices each having a semiconductor integrated circuit used therein. A signal source circuit 21, a light emitting element driver circuit 22 for supplying a signal outputted from the signal source circuit to a light emitting element 11 as a drive signal, and a light emitting element connecting terminal 23 connected to the output end of the driver circuit are integrally formed on one semiconductor chip of CMOS structure which is used as a semiconductor integrated circuit 20 of the transmitting side device A. A light receiving element connecting terminal 33 supplied with a current outputted from a light receiving element 15, a current detector circuit 32 the input end of which is connected to the connecting terminal, and a signal processing circuit 31 for receiving a signal outputted from the current detector circuit to process it in a predetermined manner are integrally formed on one semiconductor chip of CMOS structure which is used as a semiconductor integrated circuit 30 of the receiving side device B.
54954168
From String Nets to Nonabelions
We discuss Hilbert spaces spanned by the set of string nets, i.e. trivalent graphs, on a lattice. We suggest some routes by which such a Hilbert space could be the low-energy subspace of a model of quantum spins on a lattice with short-ranged interactions. We then explain conditions which a Hamiltonian acting on this string net Hilbert space must satisfy in order for the system to be in the DFib (Doubled Fibonacci) topological phase, that is, be described at low energy by an SO(3)3 × SO(3)3 doubled Chern-Simons theory, with the appropriate non-abelian statistics governing the braiding of the low-lying quasiparticle excitations (nonabelions). Using the string net wavefunction, we describe the properties of this phase. Our discussion is informed by mappings of string net wavefunctions to the chromatic polynomial and the Potts model.
54896614
Galois conjugates of topological phases
Galois conjugation relates unitary conformal field theories and topological quantum field theories (TQFTs) to their nonunitary counterparts. Here we investigate Galois conjugates of quantum double models, such as the Levin-Wen model. While these Galois-conjugated Hamiltonians are typically non-Hermitian, we find that their ground-state wave functions still obey a generalized version of the usual code property (local operators do not act on the ground-state manifold) and hence enjoy a generalized topological protection. The key question addressed in this paper is whether such nonunitary topological phases can also appear as the ground states of Hermitian Hamiltonians. Specific attempts at constructing Hermitian Hamiltonians with these ground states lead to a loss of the code property and topological protection of the degenerate ground states. Beyond this, we rigorously prove that no local change of basis can transform the ground states of the Galois-conjugated doubled Fibonacci theory into the ground states of a topological model whose Hermitian Hamiltonian satisfies Lieb-Robinson bounds. These include all gapped local or quasilocal Hamiltonians. A similar statement holds for many other nonunitary TQFTs. One consequence is that these nonunitary TQFTs do not describe physical realizations of topological phases. In particular, this implies that the ``Gaffnian'' wave function can not be the ground state of a gapped fractional quantum Hall state.
11394439
Identifying topological order by entanglement entropy
Topological entanglement entropy provides a robust measure for detecting the long-range entanglement that characterizes quantum ground states displaying topological order. A new method for calculating this entropy isolates minimally entangled states from the ground states of a topological phase—offering a reliable test for identifying topological spin liquids.
18058928
Density of the SO(3) TQFT Representation of Mapping Class Groups
We show that for an odd prime r>3 and an integer g>1, in the projective representation given by the SO(3) Witten-Reshitikhin-Turaev theory at an rth root of unity, the image of the mapping class group of a surface of genus g is dense.
19017470
Topological properties of Abelian and non-Abelian quantum Hall states classified using patterns of zeros
It has been shown that different Abelian and non-Abelian fractional quantum Hall states can be characterized by patterns of zeros described by sequences of integers ${{S}_{a}}$. In this paper, we will show how to use the data ${{S}_{a}}$ to calculate various topological properties of the corresponding fraction quantum Hall state, such as the number of possible quasiparticle types and their quantum numbers, as well as the actions of the quasiparticle tunneling and modular transformations on the degenerate ground states on torus.
15172685
SEARCH FOR MID-INFRARED FLUX VARIATIONS FROM THE ANOMALOUS X-RAY PULSAR 4U 0142+61
We report on our Spitzer observations of the anomalous X-ray pulsar 4U 0142+61, made following a large X-ray burst that occurred on 2007 February 7. To search for mid-infrared flux variations, four imaging observations were carried out at 4.5 and 8.0 μm with the Infrared Array Camera from February 14 to 21. No significant flux variations were detected, and the average fluxes were 32.1 ± 2.0 μJy at 4.5 μm and 59.8 ± 8.5 μJy at 8.0 μm, consistent with those obtained in 2005. The nondetection of variability is interesting in light of reported rapid variability from this source in the near-infrared but consistent with the fact that the source already went back to its quiescent state before our observations began, as indicated by contemporaneous X-ray observations. In order to understand the origin of the near-infrared variability, frequent, simultaneous multiwavelength observations are needed.
26132013
Towards hard x-ray imaging at GHz frame rate.
Gigahertz (GHz) imaging using hard x-rays (> or approximately equal to 10 keV) can be useful to high-temperature plasma experiments, as well as research and applications using coherent photons from synchrotron radiation and x-ray free electron lasers. GHz framing rate can be achieved by using multiple cameras through multiplexing. The advantages and trade-offs of single-photon detection mode, when no more than one x-ray photon is detected per pixel, are given. Two possible paths towards x-ray imaging at GHz frame rates using a single camera are: (a) avalanche photodiode arrays of high-Z materials and (b) microchannel plate photomultipliers in conjunction with materials with large indices of refraction.
55304030
CSIP – A Novel Photon-Counting Detector Applicable for the SPICA Far-Infrared Instrument
We describe a novel GaAs/AlGaAs double-quantumwell device for the infrared photon detection, called ChargeSensitive Infrared Phototransistor (CSIP). The principle of CSIP detector is the photo-excitation of an intersubband transition in a QW as an charge integrating gate and the signal ampliﬁcation by another QW as a channel with very high gain, which provides us with extremely high responsivity (10 4 – 10 6 A/W). It has been demonstrated that the CSIP designed for the mid-infrared wavelength (14.7 μm) has an excellent sensitivity; the noise equivalent power (NEP) of 7 × 10 -19 W/ with the quantum effciency of ~ 2%. Advantages of the CSIP against the other highly sensitive detectors are, huge dynamic range of > 10 6 , low output impedance of 10 3 – 10 4 Ohms, and relatively high operation temperature (> 2 K). We discuss possible applications of the CSIP to FIR photon detection covering 35 – 60 μm waveband, which is a gap uncovered with presently available photoconductors.
54803118
Analysis of the scalar doubly heavy tetraquark states with QCD sum rules
In this article, we perform a detailed study of the mass spectrum of the scalar doubly charmed and doubly bottom tetraquark states using the QCD sum rules.
118530343
Tracking fast neutrons
Abstract Both neutron absorption and elastic scattering can be used to measure neutron momentum. Based on elastic collisions, the linear momentum of a fast neutron can be measured from as few as two consecutive recoil ion tracks plus the vertex position of the third collision, or ‘two and half’ ion tracks. If the time delay between the first two consecutive ion tracks is also measured, the number of ion tracks can be reduced to one and a half. The angular and magnitude resolutions are limited by ion range straggling to about 10%. Multi-wire proportional chambers and light-field imaging can be used for fast neutron tracking. Light-field imaging is free of charge-diffusion-induced image blur, but the limited number of photons available can be a challenge. 1 H, 2 H and 3 He could be used for the initial development of fast neutron trackers based on light-field imaging.