Entanglement entropy of integer Quantum Hall states

We compute the entanglement entropy, in real space, of the ground state of the integer Quantum Hall states for three different domains embedded in the torus, the disk and the sphere. We establish the validity of the area law with a vanishing value of the topological entanglement entropy. The entropy per unit length of the perimeter depends on the filling fraction, but it is independent of the geometry.Comment: 5 pages, 2 figures, minor changes, one reference adde

Edge excitations of the Chern Simons matrix theory for the FQHE

We study the edge excitations of the Chern Simons matrix theory, describing the Laughlin fluids for filling fraction $\nu=\frac{1}{k}$, with $k$ an integer. Based on the semiclassical solutions of the theory, we are able to identify the bulk and edge degrees of freedom. In this way we can freeze the bulk of the theory, to the semiclassical values, obtaining an effective theory governing the boundary excitations of the Chern Simons matrix theory. Finally, we show that this effective theory is equal to the chiral boson theory on the circle.Comment: 22 pages. Section 3.2. improved. 2 Appendices added. Accepted for publication in JHE

Neural-Network Quantum States, String-Bond States, and Chiral Topological States

Neural-Network Quantum States have been recently introduced as an Ansatz for describing the wave function of quantum many-body systems. We show that there are strong connections between Neural-Network Quantum States in the form of Restricted Boltzmann Machines and some classes of Tensor-Network states in arbitrary dimensions. In particular we demonstrate that short-range Restricted Boltzmann Machines are Entangled Plaquette States, while fully connected Restricted Boltzmann Machines are String-Bond States with a nonlocal geometry and low bond dimension. These results shed light on the underlying architecture of Restricted Boltzmann Machines and their efficiency at representing many-body quantum states. String-Bond States also provide a generic way of enhancing the power of Neural-Network Quantum States and a natural generalization to systems with larger local Hilbert space. We compare the advantages and drawbacks of these different classes of states and present a method to combine them together. This allows us to benefit from both the entanglement structure of Tensor Networks and the efficiency of Neural-Network Quantum States into a single Ansatz capable of targeting the wave function of strongly correlated systems. While it remains a challenge to describe states with chiral topological order using traditional Tensor Networks, we show that Neural-Network Quantum States and their String-Bond States extension can describe a lattice Fractional Quantum Hall state exactly. In addition, we provide numerical evidence that Neural-Network Quantum States can approximate a chiral spin liquid with better accuracy than Entangled Plaquette States and local String-Bond States. Our results demonstrate the efficiency of neural networks to describe complex quantum wave functions and pave the way towards the use of String-Bond States as a tool in more traditional machine-learning applications.Comment: 15 pages, 7 figure

Frequency-selective near-field enhancement of radiative heat transfer via photonic-crystal slabs: a general computational approach for arbitrary geometries and materials

We demonstrate the possibility of achieving enhanced frequency-selective near-field radiative heat transfer between patterned (photonic crystal) slabs at designable frequencies and separations, exploiting a general numerical approach for computing heat transfer in arbitrary geometries and materials based on the finite-difference time-domain method. Our simulations reveal a tradeoff between selectivity and near-field enhancement as the slab--slab separation decreases, with the patterned heat transfer eventually reducing to the unpatterned result multiplied by a fill factor (described by a standard proximity approximation). We also find that heat transfer can be further enhanced at selective frequencies when the slabs are brought into a glide-symmetric configuration, a consequence of the degeneracies associated with the non-symmorphic symmetry group

Matrix Effective Theories of the Fractional Quantum Hall effect

The present understanding of nonperturbative ground states in the fractional quantum Hall effect is based on effective theories of the Jain \composite fermion" excitations. We review the approach based on matrix variables, i.e. D0 branes, originally introduced by Susskind and Polychronakos. We show that the Maxwell-Chern-Simons matrix gauge theory provides a matrix generalization of the quantum Hall effect, where the composite-fermion construction naturally follows from gauge invariance. The matrix ground states obtained by suitable projections of higher Landau levels are found to be in one-to-one correspondence with the Laughlin and Jain hierarchical states. The matrix theory possesses a physical limit for commuting matrices that could be reachable while staying in the same phase

KELT-10b: The First Transiting Exoplanet from the KELT-South Survey -- A Hot Sub-Jupiter Transiting a V = 10.7 Early G-Star

We report the discovery of KELT-10b, the first transiting exoplanet discovered using the KELT-South telescope. KELT-10b is a highly inflated sub-Jupiter mass planet transiting a relatively bright $V = 10.7$ star (TYC 8378-64-1), with T$_{eff}$ = $5948\pm74$ K, $\log{g}$ = $4.319_{-0.030}^{+0.020}$ and [Fe/H] = $0.09_{-0.10}^{+0.11}$, an inferred mass M$_{*}$ = $1.112_{-0.061}^{+0.055}$ M$_{\odot}$ and radius R$_{*}$ = $1.209_{-0.035}^{+0.047}$ R$_{\odot}$. The planet has a radius R$_{P}$ = $1.399_{-0.049}^{+0.069}$ R$_{J}$ and mass M$_{P}$ = $0.679_{-0.038}^{+0.039}$ M$_{J}$. The planet has an eccentricity consistent with zero and a semi-major axis $a$ = $0.05250_{-0.00097}^{+0.00086}$ AU. The best fitting linear ephemeris is $T_{0}$ = 2457066.72045$\pm$0.00027 BJD$_{TDB}$ and P = 4.1662739$\pm$0.0000063 days. This planet joins a group of highly inflated transiting exoplanets with a radius much larger and a mass much less than those of Jupiter. The planet, which boasts deep transits of 1.4%, has a relatively high equilibrium temperature of T$_{eq}$ = $1377_{-23}^{+28}$ K, assuming zero albedo and perfect heat redistribution. KELT-10b receives an estimated insolation of $0.817_{-0.054}^{+0.068}$ $\times$ 10$^9$ erg s$^{-1}$ cm$^{-2}$, which places it far above the insolation threshold above which hot Jupiters exhibit increasing amounts of radius inflation. Evolutionary analysis of the host star suggests that KELT-10b is unlikely to survive beyond the current subgiant phase, due to a concomitant in-spiral of the planet over the next $\sim$1 Gyr. The planet transits a relatively bright star and exhibits the third largest transit depth of all transiting exoplanets with V $<$ 11 in the southern hemisphere, making it a promising candidate for future atmospheric characterization studies.Comment: 20 pages, 13 figures, 7 tables, accepted for publication in MNRA

Jain States in a Matrix Theory of the Quantum Hall Effect

The U(N) Maxwell-Chern-Simons matrix gauge theory is proposed as an extension of Susskind's noncommutative approach. The theory describes D0-branes, nonrelativistic particles with matrix coordinates and gauge symmetry, that realize a matrix generalization of the quantum Hall effect. Matrix ground states obtained by suitable projections of higher Landau levels are found to be in one-to-one correspondence with the expected Laughlin and Jain hierarchical states. The Jain composite-fermion construction follows by gauge invariance via the Gauss law constraint. In the limit of commuting, ``normal'' matrices the theory reduces to eigenvalue coordinates that describe realistic electrons with Calogero interaction. The Maxwell-Chern-Simons matrix theory improves earlier noncommutative approaches and could provide another effective theory of the fractional Hall effect.Comment: 35 pages, 3 figure

KELT-11b: A Highly Inflated Sub-Saturn Exoplanet Transiting the V=8 Subgiant HD 93396

We report the discovery of a transiting exoplanet, KELT-11b, orbiting the bright ($V=8.0$) subgiant HD 93396. A global analysis of the system shows that the host star is an evolved subgiant star with $T_{\rm eff} = 5370\pm51$ K, $M_{*} = 1.438_{-0.052}^{+0.061} M_{\odot}$, $R_{*} = 2.72_{-0.17}^{+0.21} R_{\odot}$, log $g_*= 3.727_{-0.046}^{+0.040}$, and [Fe/H]$= 0.180\pm0.075$. The planet is a low-mass gas giant in a $P = 4.736529\pm0.00006$ day orbit, with $M_{P} = 0.195\pm0.018 M_J$, $R_{P}= 1.37_{-0.12}^{+0.15} R_J$, $\rho_{P} = 0.093_{-0.024}^{+0.028}$ g cm$^{-3}$, surface gravity log ${g_{P}} = 2.407_{-0.086}^{+0.080}$, and equilibrium temperature $T_{eq} = 1712_{-46}^{+51}$ K. KELT-11 is the brightest known transiting exoplanet host in the southern hemisphere by more than a magnitude, and is the 6th brightest transit host to date. The planet is one of the most inflated planets known, with an exceptionally large atmospheric scale height (2763 km), and an associated size of the expected atmospheric transmission signal of 5.6%. These attributes make the KELT-11 system a valuable target for follow-up and atmospheric characterization, and it promises to become one of the benchmark systems for the study of inflated exoplanets.Comment: 15 pages, Submitted to AAS Journal