1. 7 Sep 2022 Journal Article ACS Energy Letters

    Persistent Ion Accumulation at Interfaces Improves the Performance of Perovskite Solar Cells

    Joshua A Kress, Claudio Quarti, Qingzhi An, Sapir Bitton, Nir Tessler, David Beljonne, Yana Vaynzof
    Abstract

    The mixed ionic–electronic nature of lead halide perovskites makes their performance in solar cells complex in nature. Ion migration is often associated with negative impacts─such as hysteresis or device degradation─leading to significant efforts to suppress ionic movement in perovskite solar cells. In this work, we demonstrate that ion trapping at the perovskite/electron

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  2. 25 Aug 2022 Preprint arXiv

    Composable Security of Generalized BB84 Protocols Against General Attacks

    Michel Boyer, Rotem Liss, Tal Mor
    Abstract

    Quantum key distribution (QKD) protocols make it possible for two parties to generate a secret shared key. One of the most important QKD protocols, BB84, was suggested by Bennett and Brassard in 1984. Various proofs of unconditional security for BB84 have been suggested, but the first security proofs were not composable. Here we improve a security proof of BB84 given

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  3. 22 Aug 2022 Preprint arXiv

    Dark Grand Unification in the Axiverse: Decaying Axion Dark Matter and Spontaneous Baryogenesis

    Joshua W Foster, Soubhik Kumar, Benjamin R Safdi, Yotam Soreq
    Abstract

    The quantum chromodynamics axion with a decay constant near the Grand Unification (GUT) scale has an ultralight mass near a neV. We show, however, that axion-like particles with masses near the keV - PeV range with GUT-scale decay constants are also well motivated in that they naturally arise from axiverse theories with dark non-abelian gauge groups. We demonstrate that

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  4. 19 Aug 2022 Journal Article Physical Review Applied

    Quantum Tomography of Entangled Spin-Multiphoton States

    Abstract

    We present a method for quantum tomography of multiqubit states. We apply the method to spin-multiphoton states, which we generate using a quantum dot based device. Periodic excitation of a quantum dot confined spin deterministically generates strings of entangled photons in a cluster state, threefold faster than previously demonstrated. Our tomography method uses

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  5. 10 Aug 2022 Preprint arXiv

    Degenerate Raman sideband cooling of 40K atoms

    Abstract

    We report on the implementation of degenerate Raman sideband cooling of $^{40}$K atoms. The scheme incorporates a 3D optical lattice, which confines the atoms and drives the Raman transitions. The optical cooling cycle is closed by two optical pumping beams. The wavelength of the laser beams forming the lattice is close to the D$_2$ atomic transition, while the optical

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  6. 8 Aug 2022 Journal Article Journal of Physics A: Mathematical and Theoretical

    Disentanglement and a nonlinear Schrödinger equation

    Abstract

    We explore a nonlinear term that can be added to the Schrödinger equation without violating unitarity of the time evolution. We find that the added term suppresses entanglement, without affecting the evolution of any product state. The dynamics generated by the modified Schrödinger equation is explored for the case of a two-spin 1/2 system.

  7. 1 Aug 2022 Journal Article ACS Nano

    Optically Detected Magnetic Resonance Spectroscopy of Cu-Doped CdSe/CdS and CuInS2 Colloidal Quantum Dots

    Adi Harchol, Yahel Barak, Kira E Hughes, Kimberly H Hartstein, Huygen j Jöbsis, P Tim Prins, Celso de Mello Donegá, Daniel R Gamelin, Efrat Lifshitz
    Abstract

    Copper-doped II–VI and copper-based I–III–VI2 colloidal quantum dots (CQDs) have been at the forefront of interest in nanocrystals over the past decade, attributable to their optically activated copper states. However, the related recombination mechanisms are still unclear. The current work elaborates on recombination processes in such materials by following the spin

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  8. 29 Jul 2022 Journal Article Physical Review B

    Phonon-induced modification of quantum criticality

    Abstract

    We study the effect of acoustic phonons on the quantum phase transition in the O ( N ) model. We develop a renormalization group (RG) analysis near ( 3 + 1 ) space-time dimensions and derive the RG equations using an ε expansion. Our results indicate

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  9. 27 Jul 2022 Journal Article Nature

    Magnetic memory and spontaneous vortices in a van der Waals superconductor

    Eylon Persky, Anders Bjørlig, Irena Feldman, A Almoalem, Ehud Altman, Erez Berg, Itamar Kimchi, Jonathan Ruhman, Amit Kanigel, Beena Kalisky
    Abstract

    Doped Mott insulators exhibit some of the most intriguing quantum phases of matter, including quantum spin liquids, unconventional superconductors and non-Fermi liquid metals1,2,3. Such phases often arise when itinerant electrons are close to a Mott insulating state, and thus experience strong spatial correlations. Proximity between different layers of van der Waals

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  10. 15 Jul 2022 Conference Paper Imaging Systems and Applications 2022

    Beyond the Quantum Optical Diffraction Limit

    Abstract

    To circumvent Heisenberg’s uncertainty principle, we multiplied the number of white light photons using a dye. With larger wave-packets, the resolution is improved, as if with a larger aperture, but longer integration times are necessary.