The Experts below are selected from a list of 47706 Experts worldwide ranked by ideXlab platform

Eva Y Andrei - One of the best experts on this subject based on the ideXlab platform.

  • inducing kondo screening of vacancy magnetic moments in graphene with gating and Local Curvature
    arXiv: Mesoscale and Nanoscale Physics, 2019
    Co-Authors: Yuhang Jiang, Daniel May, G Y Guo, Frithjof B Anders, Takashi Taniguchi, Jinhai Mao, Kenji Watanabeand, Eva Y Andrei
    Abstract:

    In normal metals, the magnetic-moment of impurity-spins disappears below a characteristic Kondo temperature, TK. This marks the formation of a polarized cloud of conduction band electrons that screen the magnetic moment . In contrast, moments embedded in insulators remain unscreened at all temperatures. This raises the question about the fate of magnetic-moments in intermediate, pseudogap systems, such as graphene. In these systems coupling between the Local moment and the conduction band electrons is predicted to drive a quantum phase-transition between a Local-moment phase and a Kondo-screened singlet phase as illustrated in Fig. 1A. However, attempts to experimentally confirm these predictions and their intriguing consequences such as the ability to electrostatically tune magnetic-moments, have been elusive. Here we report the observation of Kondo screening and the quantum phase-transition between screened and unscreened phases of vacancy magnetic-moments in graphene. Using scanning-tunneling-microscopy (STM), spectroscopy (STS) and numerical-renormalization-group (NRG) calculations, we identified Kondo-screening by its spectroscopic signature and mapped the quantum phase-transition as a function of coupling strength and chemical potential. We show that the coupling strength can be tuned across this transition by variations in the Local Curvature and furthermore that the transition makes it possible to turn the magnetic-moment on and off with a gate voltage.

  • inducing kondo screening of vacancy magnetic moments in graphene with gating and Local Curvature
    Nature Communications, 2018
    Co-Authors: Yuhang Jiang, Daniel May, G Y Guo, Frithjof B Anders, Takashi Taniguchi, Kenji Watanabe, Jinhai Mao, Eva Y Andrei
    Abstract:

    In normal metals the magnetic moment of impurity-spins disappears below a characteristic Kondo temperature which marks the formation of a cloud of conduction-band electrons that screen the Local-moment. In contrast, moments embedded in insulators remain unscreened at all temperatures. What then is the fate of magnetic-moments in intermediate, pseudogap systems, such as graphene? Theory predicts that coupling to the conduction-band electrons will drive a quantum phase transition between a Local-moment phase and a Kondo-screened phase. However, attempts to experimentally confirm this prediction and its intriguing consequences, such as electrostatically tunable magnetic-moments, have been elusive. Here we report the observation of Kondo-screening and the quantum phase-transition between screened and unscreened phases of vacancy magnetic moments in graphene. Using scanning tunneling spectroscopy and numerical renormalization-group calculations we show that this transition enables to control the screening of Local moments by tuning the gate voltage and the Local Curvature of the graphene membrane.

Jinhai Mao - One of the best experts on this subject based on the ideXlab platform.

  • inducing kondo screening of vacancy magnetic moments in graphene with gating and Local Curvature
    arXiv: Mesoscale and Nanoscale Physics, 2019
    Co-Authors: Yuhang Jiang, Daniel May, G Y Guo, Frithjof B Anders, Takashi Taniguchi, Jinhai Mao, Kenji Watanabeand, Eva Y Andrei
    Abstract:

    In normal metals, the magnetic-moment of impurity-spins disappears below a characteristic Kondo temperature, TK. This marks the formation of a polarized cloud of conduction band electrons that screen the magnetic moment . In contrast, moments embedded in insulators remain unscreened at all temperatures. This raises the question about the fate of magnetic-moments in intermediate, pseudogap systems, such as graphene. In these systems coupling between the Local moment and the conduction band electrons is predicted to drive a quantum phase-transition between a Local-moment phase and a Kondo-screened singlet phase as illustrated in Fig. 1A. However, attempts to experimentally confirm these predictions and their intriguing consequences such as the ability to electrostatically tune magnetic-moments, have been elusive. Here we report the observation of Kondo screening and the quantum phase-transition between screened and unscreened phases of vacancy magnetic-moments in graphene. Using scanning-tunneling-microscopy (STM), spectroscopy (STS) and numerical-renormalization-group (NRG) calculations, we identified Kondo-screening by its spectroscopic signature and mapped the quantum phase-transition as a function of coupling strength and chemical potential. We show that the coupling strength can be tuned across this transition by variations in the Local Curvature and furthermore that the transition makes it possible to turn the magnetic-moment on and off with a gate voltage.

  • inducing kondo screening of vacancy magnetic moments in graphene with gating and Local Curvature
    Nature Communications, 2018
    Co-Authors: Yuhang Jiang, Daniel May, G Y Guo, Frithjof B Anders, Takashi Taniguchi, Kenji Watanabe, Jinhai Mao, Eva Y Andrei
    Abstract:

    In normal metals the magnetic moment of impurity-spins disappears below a characteristic Kondo temperature which marks the formation of a cloud of conduction-band electrons that screen the Local-moment. In contrast, moments embedded in insulators remain unscreened at all temperatures. What then is the fate of magnetic-moments in intermediate, pseudogap systems, such as graphene? Theory predicts that coupling to the conduction-band electrons will drive a quantum phase transition between a Local-moment phase and a Kondo-screened phase. However, attempts to experimentally confirm this prediction and its intriguing consequences, such as electrostatically tunable magnetic-moments, have been elusive. Here we report the observation of Kondo-screening and the quantum phase-transition between screened and unscreened phases of vacancy magnetic moments in graphene. Using scanning tunneling spectroscopy and numerical renormalization-group calculations we show that this transition enables to control the screening of Local moments by tuning the gate voltage and the Local Curvature of the graphene membrane.

Yuhang Jiang - One of the best experts on this subject based on the ideXlab platform.

  • inducing kondo screening of vacancy magnetic moments in graphene with gating and Local Curvature
    arXiv: Mesoscale and Nanoscale Physics, 2019
    Co-Authors: Yuhang Jiang, Daniel May, G Y Guo, Frithjof B Anders, Takashi Taniguchi, Jinhai Mao, Kenji Watanabeand, Eva Y Andrei
    Abstract:

    In normal metals, the magnetic-moment of impurity-spins disappears below a characteristic Kondo temperature, TK. This marks the formation of a polarized cloud of conduction band electrons that screen the magnetic moment . In contrast, moments embedded in insulators remain unscreened at all temperatures. This raises the question about the fate of magnetic-moments in intermediate, pseudogap systems, such as graphene. In these systems coupling between the Local moment and the conduction band electrons is predicted to drive a quantum phase-transition between a Local-moment phase and a Kondo-screened singlet phase as illustrated in Fig. 1A. However, attempts to experimentally confirm these predictions and their intriguing consequences such as the ability to electrostatically tune magnetic-moments, have been elusive. Here we report the observation of Kondo screening and the quantum phase-transition between screened and unscreened phases of vacancy magnetic-moments in graphene. Using scanning-tunneling-microscopy (STM), spectroscopy (STS) and numerical-renormalization-group (NRG) calculations, we identified Kondo-screening by its spectroscopic signature and mapped the quantum phase-transition as a function of coupling strength and chemical potential. We show that the coupling strength can be tuned across this transition by variations in the Local Curvature and furthermore that the transition makes it possible to turn the magnetic-moment on and off with a gate voltage.

  • inducing kondo screening of vacancy magnetic moments in graphene with gating and Local Curvature
    Nature Communications, 2018
    Co-Authors: Yuhang Jiang, Daniel May, G Y Guo, Frithjof B Anders, Takashi Taniguchi, Kenji Watanabe, Jinhai Mao, Eva Y Andrei
    Abstract:

    In normal metals the magnetic moment of impurity-spins disappears below a characteristic Kondo temperature which marks the formation of a cloud of conduction-band electrons that screen the Local-moment. In contrast, moments embedded in insulators remain unscreened at all temperatures. What then is the fate of magnetic-moments in intermediate, pseudogap systems, such as graphene? Theory predicts that coupling to the conduction-band electrons will drive a quantum phase transition between a Local-moment phase and a Kondo-screened phase. However, attempts to experimentally confirm this prediction and its intriguing consequences, such as electrostatically tunable magnetic-moments, have been elusive. Here we report the observation of Kondo-screening and the quantum phase-transition between screened and unscreened phases of vacancy magnetic moments in graphene. Using scanning tunneling spectroscopy and numerical renormalization-group calculations we show that this transition enables to control the screening of Local moments by tuning the gate voltage and the Local Curvature of the graphene membrane.

Ian Bennion - One of the best experts on this subject based on the ideXlab platform.

  • Two-axis bend measurement with Bragg gratings in multicore optical fiber
    Optics letters, 2003
    Co-Authors: Gordon M. H. Flockhart, J D C Jones, William N. Macpherson, Lin Zhang, James S. Barton, Ian Bennion
    Abstract:

    We describe what is to our knowledge the first use of fiber Bragg gratings written into three separate cores of a multicore fiber for two-axis Curvature measurement. The gratings act as independent, but isothermal, fiber strain gauges for which Local Curvature determines the difference in strain between cores, permitting temperature-independent bend measurement.

  • bend measurement using bragg gratings in multicore fibre
    Electronics Letters, 2000
    Co-Authors: Martin J Gander, Paul M Blanchard, James G Burnett, R. Mcbride, Ian Bennion, J D C Jones, William N. Macpherson, Lin Zhang, A. H. Greenaway
    Abstract:

    The first measurements of Curvature made using Bragg gratings written in separate cores of a multicore optical fibre are described. The gratings act as independent, but isothermal, strain gauges. The difference in Bragg wavelength between the gratings provides a temperature-independent measurement of the Local Curvature.

Frithjof B Anders - One of the best experts on this subject based on the ideXlab platform.

  • inducing kondo screening of vacancy magnetic moments in graphene with gating and Local Curvature
    arXiv: Mesoscale and Nanoscale Physics, 2019
    Co-Authors: Yuhang Jiang, Daniel May, G Y Guo, Frithjof B Anders, Takashi Taniguchi, Jinhai Mao, Kenji Watanabeand, Eva Y Andrei
    Abstract:

    In normal metals, the magnetic-moment of impurity-spins disappears below a characteristic Kondo temperature, TK. This marks the formation of a polarized cloud of conduction band electrons that screen the magnetic moment . In contrast, moments embedded in insulators remain unscreened at all temperatures. This raises the question about the fate of magnetic-moments in intermediate, pseudogap systems, such as graphene. In these systems coupling between the Local moment and the conduction band electrons is predicted to drive a quantum phase-transition between a Local-moment phase and a Kondo-screened singlet phase as illustrated in Fig. 1A. However, attempts to experimentally confirm these predictions and their intriguing consequences such as the ability to electrostatically tune magnetic-moments, have been elusive. Here we report the observation of Kondo screening and the quantum phase-transition between screened and unscreened phases of vacancy magnetic-moments in graphene. Using scanning-tunneling-microscopy (STM), spectroscopy (STS) and numerical-renormalization-group (NRG) calculations, we identified Kondo-screening by its spectroscopic signature and mapped the quantum phase-transition as a function of coupling strength and chemical potential. We show that the coupling strength can be tuned across this transition by variations in the Local Curvature and furthermore that the transition makes it possible to turn the magnetic-moment on and off with a gate voltage.

  • inducing kondo screening of vacancy magnetic moments in graphene with gating and Local Curvature
    Nature Communications, 2018
    Co-Authors: Yuhang Jiang, Daniel May, G Y Guo, Frithjof B Anders, Takashi Taniguchi, Kenji Watanabe, Jinhai Mao, Eva Y Andrei
    Abstract:

    In normal metals the magnetic moment of impurity-spins disappears below a characteristic Kondo temperature which marks the formation of a cloud of conduction-band electrons that screen the Local-moment. In contrast, moments embedded in insulators remain unscreened at all temperatures. What then is the fate of magnetic-moments in intermediate, pseudogap systems, such as graphene? Theory predicts that coupling to the conduction-band electrons will drive a quantum phase transition between a Local-moment phase and a Kondo-screened phase. However, attempts to experimentally confirm this prediction and its intriguing consequences, such as electrostatically tunable magnetic-moments, have been elusive. Here we report the observation of Kondo-screening and the quantum phase-transition between screened and unscreened phases of vacancy magnetic moments in graphene. Using scanning tunneling spectroscopy and numerical renormalization-group calculations we show that this transition enables to control the screening of Local moments by tuning the gate voltage and the Local Curvature of the graphene membrane.