Institution
École Polytechnique Fédérale de Lausanne
Facility•Lausanne, Switzerland•
About: École Polytechnique Fédérale de Lausanne is a facility organization based out in Lausanne, Switzerland. It is known for research contribution in the topics: Population & Catalysis. The organization has 44041 authors who have published 98296 publications receiving 4372092 citations. The organization is also known as: EPFL & ETHL.
Topics: Population, Catalysis, Computer science, Laser, Context (language use)
Papers published on a yearly basis
Papers
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TL;DR: In this article, the existence of superfluidity in polaritons is investigated in terms of the Landau criterion and manifests itself as the suppression of scattering from defects when the flow velocity is slower than the speed of sound in the fluid.
Abstract: Similar to atoms in cold gases, exciton–polaritons in semiconductor microcavities can undergo Bose–Einstein condensation. A striking consequence of the appearance of macroscopic coherence in these systems is superfluidity. Now, clear evidence for such behaviour has been found in an exciton–polariton condensate. Superfluidity, the ability of a quantum fluid to flow without friction, is one of the most spectacular phenomena occurring in degenerate gases of interacting bosons. Since its first discovery in liquid helium-4 (refs 1, 2), superfluidity has been observed in quite different systems, and recent experiments with ultracold trapped atoms have explored the subtle links between superfluidity and Bose–Einstein condensation3,4,5. In solid-state systems, it has been anticipated that exciton–polaritons in semiconductor microcavities should behave as an unusual quantum fluid6,7,8, with unique properties stemming from its intrinsically non-equilibrium nature. This has stimulated the quest for an experimental demonstration of superfluidity effects in polariton systems9,10,11,12,13. Here, we report clear evidence for superfluid motion of polaritons. Superfluidity is investigated in terms of the Landau criterion and manifests itself as the suppression of scattering from defects when the flow velocity is slower than the speed of sound in the fluid. Moreover, a Cerenkov-like wake pattern is observed when the flow velocity exceeds the speed of sound. The experimental findings are in quantitative agreement with predictions based on a generalized Gross–Pitaevskii theory12,13, and establish microcavity polaritons as a system for exploring the rich physics of non-equilibrium quantum fluids.
820 citations
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TL;DR: Measurements of a phononic quadrupole topological insulator are reported and topological corner states are found that are an important stepping stone to the experimental realization of topologically protected wave guides in higher dimensions, and thereby open up a new path for the design of metamaterials.
Abstract: The modern theory of charge polarization in solids is based on a generalization of Berry’s phase. The possibility of the quantization of this phase arising from parallel transport in momentum space is essential to our understanding of systems with topological band structures. Although based on the concept of charge polarization, this same theory can also be used to characterize the Bloch bands of neutral bosonic systems such as photonic or phononic crystals. The theory of this quantized polarization has recently been extended from the dipole moment to higher multipole moments. In particular, a two-dimensional quantized quadrupole insulator is predicted to have gapped yet topological one-dimensional edge modes, which stabilize zero-dimensional in-gap corner states. However, such a state of matter has not previously been observed experimentally. Here we report measurements of a phononic quadrupole topological insulator. We experimentally characterize the bulk, edge and corner physics of a mechanical metamaterial (a material with tailored mechanical properties) and find the predicted gapped edge and in-gap corner states. We corroborate our findings by comparing the mechanical properties of a topologically non-trivial system to samples in other phases that are predicted by the quadrupole theory. These topological corner states are an important stepping stone to the experimental realization of topologically protected wave guides in higher dimensions, and thereby open up a new path for the design of metamaterials.
818 citations
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TL;DR: This work presents the first crystal structure of an active laccase containing a full complement of coppers, the complete polypeptide chain together with seven carbohydrate moieties, and a mechanism is presented to explain how laccases could tune their redox potential by as much as 200 mV.
817 citations
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TL;DR: In vivo analysis revealed that MLP-deficient mice reproduce the morphological and clinical picture of dilated cardiomyopathy and heart failure in humans, providing the first model for this condition in a genetically manipulatable organism.
816 citations
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TL;DR: In this paper, the shape and elasticity of dura mater, the protective membrane of the brain and spinal cord, was designed and fabricated for implantable neuroprostheses, which embeds interconnects, electrodes and chemotrodes that sustain millions of mechanical stretch cycles, electrical stimulation pulses, and chemical injections.
Abstract: The mechanical mismatch between soft neural tissues and stiff neural implants hinders the long-term performance of implantable neuroprostheses. Here, we designed and fabricated soft neural implants with the shape and elasticity of dura mater, the protective membrane of the brain and spinal cord. The electronic dura mater, which we call e-dura, embeds interconnects, electrodes, and chemotrodes that sustain millions of mechanical stretch cycles, electrical stimulation pulses, and chemical injections. These integrated modalities enable multiple neuroprosthetic applications. The soft implants extracted cortical states in freely behaving animals for brain-machine interface and delivered electrochemical spinal neuromodulation that restored locomotion after paralyzing spinal cord injury.
812 citations
Authors
Showing all 44420 results
Name | H-index | Papers | Citations |
---|---|---|---|
Michael Grätzel | 248 | 1423 | 303599 |
Ruedi Aebersold | 182 | 879 | 141881 |
Eliezer Masliah | 170 | 982 | 127818 |
Richard H. Friend | 169 | 1182 | 140032 |
G. A. Cowan | 159 | 2353 | 172594 |
Ian A. Wilson | 158 | 971 | 98221 |
Johan Auwerx | 158 | 653 | 95779 |
Menachem Elimelech | 157 | 547 | 95285 |
A. Artamonov | 150 | 1858 | 119791 |
Melody A. Swartz | 148 | 1304 | 103753 |
Henry J. Snaith | 146 | 511 | 123155 |
Kurt Wüthrich | 143 | 739 | 103253 |
Richard S. J. Frackowiak | 142 | 309 | 100726 |
Jean-Paul Kneib | 138 | 805 | 89287 |
Kevin J. Tracey | 138 | 561 | 82791 |