Publications (24)
On the Duality of Task and Actor Programming Models
Rohan Yadav, Joseph Guman, Sean Treichler +4
Programming models for distributed and heterogeneous machines are rapidly growing in popularity to meet the demands of modern workloads. Task and actor models are common choices th…
Coherent modulation of the electron temperature and electron-phonon couplings in a 2D material
Yingchao Zhang, Xun Shi, Wenjing You +9
Ultrashort light pulses can selectively excite charges, spins and phonons in materials, providing a powerful approach for manipulating their properties. Here we use femtosecond las…
Ice Melt, Sea Level Rise and Superstorms: Evidence from Paleoclimate Data, Climate Modeling, and Modern Observations that 2°C Global Warming is Dangerous
James Hansen, Makiko Sato, Paul Hearty +16
We use numerical climate simulations, paleoclimate data, and modern observations to study the effect of growing ice melt from Antarctica and Greenland. Meltwater tends to stabilize…
Ultrafast Band-Gap Renormalization in Bilayer Graphene
Eduard Moos, Zhi-Yuan Deng, Hauke Beyer +6
We demonstrate, by femtosecond time- and angle-resolved photoemission spectroscopy, that photoinduced interlayer charge transfer in a heterostructure consisting of Bernal-stacked b…
Automatic Tracing in Task-Based Runtime Systems
Rohan Yadav, Michael Bauer, David Broman +3
Implicitly parallel task-based runtime systems often perform dynamic analysis to discover dependencies in and extract parallelism from sequential programs. Dependence analysis beco…
Efficiency of a Brownian information machine
Michael Bauer, David Abreu, Udo Seifert
A Brownian information machine extracts work from a heat bath through a feedback process that exploits the information acquired in a measurement. For the paradigmatic case of a par…
A combined laser-based ARPES and 2PPES study of Td-WTe
Petra Hein, Stephan Jauernik, Hermann Erk +5
Laser-based angle-resolved photoemission spectroscopy (ARPES) and two-photon photoemission spectroscopy (2PPES) are employed to study the valence electronic structure of the Weyl s…
Evidence for Solar-Wind Charge-Exchange X-Ray Emission from the Earth's Magnetosheath
Ryuichi Fujimoto, Kazuhisa Mitsuda, Dan McCammon +7
We report an apparent detection of the C VI 4p to 1s transition line at 459 eV, during a long-term enhancement (LTE) in the Suzaku north ecliptic pole (NEP) observation of 2005 Sep…
Decoding the ultrafast formation of a Fermi-Dirac distributed electron gas
Gerald Rohde, Ankatrin Stange, Arne Müller +7
Time- and angle-resolved photoelectron spectroscopy with 13 fs temporal resolution is used to follow the different stages in the formation of a Fermi-Dirac distributed electron gas…
Task-Based Tensor Computations on Modern GPUs
Rohan Yadav, Michael Garland, Alex Aiken +1
Domain-specific, fixed-function units are becoming increasingly common in modern processors. As the computational demands of applications evolve, the capabilities and programming i…
How to compare diffusion processes assessed by single-particle tracking and pulsed field gradient nuclear magnetic resonance
Michael Bauer, Rustem Valiullin, Günter Radons +1
Heterogeneous diffusion processes occur in many different fields such as transport in living cells or diffusion in porous media. A characterization of the transport parameters of s…
Universal Coherence-Induced Power Losses of Quantum Heat Engines in Linear Response
Kay Brandner, Michael Bauer, Udo Seifert
We introduce a universal scheme to divide the power output of a periodically driven quantum heat engine into a classical contribution and one stemming solely from quantum coherence…
Optimized finite-time information machine
Michael Bauer, Andre C. Barato, Udo Seifert
We analyze a periodic optimal finite-time two-state information-driven machine that extracts work from a single heat bath exploring imperfect measurements. Two models are considere…
Ultrafast low-energy photoelectron diffraction for the study of surface-adsorbate interactions with 100 femtosecond temporal resolution
Hermann Erk, Carl Eric Jensen, Stephan Jauernik +1
An ultrafast photoemission-based low-energy electron diffraction experiment with monolayer surface sensitivity is presented. In a first experiment on tin-phthalocyanine adsorbed on…
Optimal Software Pipelining and Warp Specialization for Tensor Core GPUs
Rupanshu Soi, Rohan Yadav, Fredrik Kjolstad +4
GPU architectures have continued to grow in complexity, with recent incarnations introducing increasingly powerful fixed-function units for matrix multiplication and data movement…
Ultrafast electron calorimetry uncovers a new long-lived metastable state in 1T-TaSe mediated by mode-selective electron-phonon coupling
Xun Shi, Wenjing You, Yingchao Zhang +8
Quantum materials represent one of the most promising frontiers in the quest for faster, lightweight, energy efficient technologies. However, their inherent complexity and rich pha…
Creation of a novel inverted charge density wave state
Yingchao Zhang, Xun Shi, Mengxue Guan +10
Charge density wave (CDW) order is an emergent quantum phase that is characterized by a periodic lattice distortion and charge density modulation, often present near superconductin…
Characterizing N-dimensional anisotropic Brownian motion by the distribution of diffusivities
Mario Heidernätsch, Michael Bauer, Günter Radons
Anisotropic diffusion processes emerge in various fields such as transport in biological tissue and diffusion in liquid crystals. In such systems, the motion is described by a diff…
Composing Distributed Computations Through Task and Kernel Fusion
Rohan Yadav, Shiv Sundram, Wonchan Lee +4
We introduce Diffuse, a system that dynamically performs task and kernel fusion in distributed, task-based runtime systems. The key component of Diffuse is an intermediate represen…
Optimal performance of periodically driven, stochastic heat engines under limited control
Michael Bauer, Kay Brandner, Udo Seifert
We consider the performance of periodically driven stochastic heat engines in the linear response regime. Reaching the theoretical bounds for efficiency and efficiency at maximum p…
Photoemission electron microscopy of exciton-polaritons in thin WSe waveguides
Tobias Eul, Miwan Sabir, Victor DeManuel-Gonzalez +3
Exciton-polaritons emerging from the interaction of photons and excitons in the strong coupling regime are intriguing quasiparticles for the potential exchange of energy during lig…
Coherence-enhanced efficiency of feedback-driven quantum engines
Kay Brandner, Michael Bauer, Michael T. Schmid +1
A genuine feature of projective quantum measurements is that they inevitably alter the mean energy of the observed system if the measured quantity does not commute with the Hamilto…
Origin of phonon decoherence
Yiming Pan, Christoph Emeis, Stephan Jauernik +2
Phonon decoherence determines the characteristic timescales over which coherent lattice vibrations decay, making it a crucial process for understanding the non-equilibrium dynamics…
Coherent Phonon-Driven Band Renormalizations in 1T-MoTe
Carl E. Jensen, Christoph Emeis, Stephan Jauernik +3
Here, we investigate phonon mode- and electron band-selective electron-phonon couplings in centrosymmetric 1T-MoTe using time- and angle-resolved photoemission spectroscopy…