All devices were prepared on silicon-on-insulator (SOI; Soitec Inc.) wafers. The SOI wafers were pre-doped by thermally diffusing spin-on-dopant (Boron A; Filmtronics, Inc.) with rapid thermal annealing (RTA) at 820C for 3 minutes. The resulting sheet resistance indicates a doping concentration of 2x10 19 cm -3 , with the thickness of the silicon epilayer determined by atomic force microscopy to be 25 nm, 22 nm and 20 nm (depending on the device) with a variance of 1 nm. The nanomesh films (NM) and nanowires (NWA) are fabricated by the SNAP technique [30], while the e-beam nanomesh (EBM) and thin films (TF) are defined by e-beam lithography (EBL).For the NM devices, two perpendicularly aligned Pt nanowire arrays are made using two consecutive superlattice nanowire pattern array (SNAP) procedures on top of an SOI wafer (Soitec, Inc.). SNAP protocols are described in Refs. 17 and 30. For the NWA devices only one SNAP procedure is carried out, resulting in a single, aligned Pt nanowire array. For the EBM and TF devices, e-beam lithography and metallization are used to make the transfer-ready Pt nanostructures. Next, we define the membranes

We report a new Ce-rich family of active oxygen evolution reaction (OER) catalysts composed of earth abundant elements, discovered using high-throughput methods. High resolution inkjet printing was used to produce 5456 discrete oxide compositions containing the elements nickel, iron, cobalt and cerium. The catalytic performance of each of these compositions was measured under conditions applicable to distributed solar fuels generation using a three-electrode scanning drop electrochemical cell. In particular, the 4-electron oxygen evolution reaction (OER) is kinetically slow and improved catalysts are required for articial photosynthesis and electrolysis of hydrogen or carbon-containing fuels.2 Because a robust fundamental understanding of the basic science and mechanistic details of multi-electron heterogeneous electrocatalysis is lacking, an efficient high-throughput synthesis and property screening methodology is well-suited to empirically discovering the requisite new catalytic materials.4-11 Ideally, the newly discovered materials will not only perform better under operational conditions, but display unique behaviors that contribute to the fundamental understanding of these complex reactions. Combinatorial methods have previously been used to search pseudoternary spaces for improved OER catalysts.7-9 To broaden the catalyst search we have developed very high throughput techniques capable of screening pseudoquaternary spaces and describe high throughput screening techniques designed specically for discovery of OER catalysts for articial photosynthesis. The effectiveness of this approach is demonstrated by our discovery of a new, highly active family of OER catalysts in an unpredicted composition space, providing new pathways for engineering optimization and OER catalysis science.Mixed metal oxides in the (Ni-Fe)O x and (Ni-Co)O x composition spaces are among the most active and most studied OER Broader contextThe development of new, environmentally friendly energy technologies critically depends upon the discovery and development of new functional materials. For example, efficient conversion of solar energy to fuels requires the discovery of new electrocatalysts, particularly for the oxygen evolution reaction (OER). Large-scale deployment of this type of system requires the discovery of improved electrocatalysts containing only earthabundant elements. Lacking a robust fundamental understanding of the basic science and mechanistic details of multi-electron heterogeneous electrocatalysis, an efficient high-throughput synthesis and property screening methodology is well-suited to discovering the requisite new catalytic materials. The effectiveness of this approach is demonstrated by our discovery of a new, highly active OER catalyst in an unpredicted composition space, displaying unusual electrochemical behavior. We describe high throughput synthesis, screening techniques and gures of merit designed specically for discovery of OER catalysts for articial photosynthesis.682 | Energy Environ. Sci., 2014, 7, ...

High-resolution angle-resolved photoemission spectroscopy ͑ARPES͒ on the quasi-one-dimensional Peierls system K 0.3 MoO 3 reveals a ''hidden'' open Fermi surface and band features displaying the symmetry properties of the underlying lattice. However, the ARPES line shapes and optical data suggest that the corresponding quasiparticles are heavily renormalized by strong electron-phonon interactions. The temperature dependence of the leading edge of the mostly incoherent spectrum bears signatures of the Peierls transition at T P ϭ180 K and of pretransitional fluctuations.

Fast Reroute (FRR) and other forms of immediate failover have long been used to recover from certain classes of failures without invoking the network control plane. While the set of such techniques is growing, the level of resiliency to failures that this approach can provide is not adequately understood. In this paper, we embarked upon a systematic algorithmic study of the resiliency of forwarding tables in a variety of models (i.e., deterministic/probabilistic routing, with packet-header-rewriting, with packet-duplication). Our results show that the resiliency of a routing scheme depends on the "connectivity" k of a network, i.e., the minimum number of link deletions that partition a network. We complement our theoretical result with extensive simulations. We show that resiliency to 4 simultaneous link failures, with limited path stretch, can be achieved without any packet modification/duplication or randomization. Furthermore, our routing schemes provide resiliency against k−1 failures, with limited path stretch, by storing log(k) bits in the packet header, with limited packet duplication, or with randomized forwarding technique.

We present O(log log n)-round algorithms in the Massively Parallel Computation (MPC) model, withÕ(n) memory per machine, that compute a maximal independent set, a 1 + ε approximation of maximum matching, and a 2 + ε approximation of minimum vertex cover, for any n-vertex graph and any constant ε > 0. These improve the state of the art as follows:• Our MIS algorithm leads to a simple O(log log ∆)-round MIS algorithm in the CONGESTED-CLIQUE model of distributed computing, which improves on theÕ( log ∆)-round algorithm of Ghaffari [PODC'17].• Our O(log log n)-round (1 + ε)-approximate maximum matching algorithm simplifies or improves on the following prior work: O(log 2 log n)-round (1 + ε)-approximation algorithm of Czumaj et al. [STOC'18] and O(log log n)-round (1 + ε)-approximation algorithm of Assadi et al. [SODA'19]. • Our O(log log n)-round (2 + ε)-approximate minimum vertex cover algorithm improves on an O(log log n)-round O(1)-approximation of Assadi et al. [arXiv'17]. The ModelsWe consider two closely related models: Massively Parallel Computation (MPC), and the CONGESTED-CLIQUE model of distributed computing. Indeed, we consider it as a conceptual contribution of this paper to (further) exhibit the proximity of these two models. We next review these models. The MPC modelThe MPC model was first introduced in [KSV10] and later refined in [GSZ11, BKS13, ANOY14].The computation in this model proceeds in synchronous rounds carried out by m machines. At the beginning of every round, the data (e.g. vertices and edges) is distributed across the machines. During a round, each machine performs computation locally without communicating to other machines. At the end of the round, the machines exchange messages which are used to guide the computation in the next round. In every round, each machine receives and outputs messages that fit into its local memory.Space: In this model, each machine has S words of space. If N is the total size of the data and each machine has S words of space, the typical settings that are of interest are when S is sublinear in N and S · m = Θ(N ). That is, the total memory across all the machines suffices to fit all the data, but is not much larger than that. If we are given a graph on n vertices, in our work we consider the regimes in which S ∈ Θ(n/ polylog n) or S ∈ Θ(n). Communication vs. computational complexity:Our main focus is the number of rounds required to finish the computation, which is essentially the complexity of the communication needed to solve the problem. Although we do not explicitly state the computational complexity in our results, it will be apparent from the description of our algorithms that the total computation time across all the machines is nearly-linear in the input size. CONGESTED-CLIQUEA second model that we consider is the CONGESTED-CLIQUE model of distributed computing, which was introduced by Lotker, Pavlov, Patt-Shamir, and Peleg [LPPSP03] and has been stud-ied extensively since then, see e.g.]. In this model, we have n players which can communicate in sync...

Fast Reroute (FRR) and other forms of immediate failover have long been used to recover from certain classes of failures without invoking the network control plane. While the set of such techniques is growing, the level of resiliency to failures that this approach can provide is not adequately understood. We embark upon a systematic algorithmic study of the resiliency of immediate failover in a variety of models (with/without packet marking/duplication, etc.). We leverage our findings to devise new schemes for immediate failover and show, both theoretically and experimentally, that these outperform existing approaches.

Supplementary Figure 1 | Thermopile and wire length analysis. a, Absorption spectra used in simulations for b,c,e,f. b, Responsivity for a structure with 50 µm long wires and 27 µm long pads, as a function of number of wires in a thermopile configuration. The entire structure is illuminated and responsivity is calculated relative to power striking the wire area. The pads are assumed to have a 20% absorption, independent of wavelength. c, Noise equivalent power (NEP) for the thermopiles in b, assuming Johnson noise as the noise spectral density using simulated average temperatures. d, Temperature difference between the edge of the pad and the center of the wires versus power density for different wire lengths. Pad sizes remain constant with dimensions of 50 µm by 27 µm by 50 nm. e, Responsivity as a function of wavelength for the absorption spectrum in a, for different wire lengths, relative to power illuminating the entire structure. f, Noise equivalent power corresponding to the responsivity in e, for different wire lengths. Noise spectral density is theoretical Johnson noise using simulated average temperatures for the structures. Simulation details are given in Supplementary Note 1.

High-resolution angle-resolved photoemission (ARPES) data show that a metal-insulator Mott transition occurs at the surface of the quasi-two dimensional compound 1T -TaSe2. The transition is driven by the narrowing of the Ta 5d band induced by a temperature-dependent modulation of the atomic positions. A dynamical mean-field theory calculation of the spectral function of the halffilled Hubbard model captures the main qualitative feature of the data, namely the rapid transfer of spectral weight from the observed quasiparticle peak at the Fermi surface to the Hubbard bands, as the correlation gap opens up.PACS numbers: 71.30.+h,79.60.Bm,71.45.Lr,71.10.Fd Electronic correlations can modify the electronic structure of solids not only quantitatively, but also qualitatively, inducing new broken-symmetry phases which exhibit charge, spin or orbital-order, and more exotic states in low dimensions. One of the most notable consequences of electronic correlations is the much studied metal-insulator (M-I) Mott transition [1,2]. Recently, new theoretical approaches have considerably extended our understanding of this fundamental problem [2,3].Many physical properties indirectly reflect the dramatic rearrangement of the electronic structure at the transition. Photoelectron spectroscopy, which probes the single-particle spectral function, can provide a direct view of such changes [4,5,6]. However, comparing samples with different compositions faces materials problems like stoichiometry, defects, and disorder. A quantitative analysis is further complicated by the known surface sensitivity of the technique [7][8]. An ideal experiment would record the energy and momentum-dependent spectrum, while tuning the crucial (W/U ) parameter (U is the onsite Coulomb correlation energy; W is the bandwidth) in the same single crystal sample. Remarkably, it is possible to approach this ideal situation exploiting the occurrence of modulated structures (charge-density-waves; CDWs) in appropriate low-dimensional systems. There, the lattice distortion modulates the transfer integrals and therefore modifies the bandwidth. In materials that are close enough to a Mott transition, the reduced bandwidth may lead to an instability. There are strong indications for this scenario in the layered chalcogenide 1T -TaS 2 , which presents a sharp order-of-magnitude increase of the resistivity at T=180 K [9, 10], with a strong rearrangement of the electronic states [11,12,13,14,15]. However, the complex phase diagram of the CDW in 1T -TaS 2 affects the electronic transition, which cannot be considered as a typical Mott transition.Isostructural and isoelectronic 1T -TaSe 2 exhibits a similar CDW, but only one phase below T C =475 K. Its electrical resistivity remains metallic -albeit rather large -to very low temperatures [9], suggesting that the Se compound lies further from the instability than the S analog. Nevertheless, a transition could still occur at the crystal surface, where the U/W ratio is expected to be larger as a result of smaller screening and...