The Experts below are selected from a list of 264 Experts worldwide ranked by ideXlab platform

Helene Bolvin - One of the best experts on this subject based on the ideXlab platform.

  • Derivation of Lanthanide Series Crystal Field Parameters From First Principles
    Chemistry - A European Journal, 2019
    Co-Authors: Julie Jung, Claude Berthon, Talal Mallah, M. Ashraful Islam, Vincent Pecoraro, Helene Bolvin
    Abstract:

    Two series of lanthanide complexes have been cho- sen to analyze trends in the magnetic properties and crystal field parameters (CFPs) along the se- ries: the highly symmetric LnZn 16 (picHA) 16 series with Ln = Tb, Dy, Ho, Er, Yb and picHA=picoline hydroxamic, and the [Ln(DPA)3 ](C3H5N2)3·3H2O series with DPA = 2,6-dipicolinic acid and Ln = Ce–Yb and with approximate three-fold symmetry. The first series presents a compressed coordination sphere of 8 oxygen atoms environment while in the 2nd series, the coordination sphere is formed by an elongated coordination sphere formed by six oxy- gen atoms. CFPs are deduced from ab initio cal- culations using two methods: the AILFT (Ab Ini- tio Ligand Field Theory) which determines the pa- rameters at the orbital Level, and the ITO (Irre- ducible Technique Operator) decomposition which treats the problem at the many-Electron Level. It is shown that the CFPs are transferable from one derivative to the other, within a given series, as a first approximation. The sign of the 2nd order pa- rameter B02 differs in the two series reflecting the different environments. It is shown that the use of strength parameter S allows for an easy com- parison between complexes. Furthermore, in both series, the parameters are found to decrease in mag- nitude along the series and this decrease is imputed

  • derivation of lanthanide series crystal field parameters from first principles
    Chemistry: A European Journal, 2019
    Co-Authors: Julie Jung, Ashraful M Islam, Vincent L Pecoraro, Claude Berthon, Talal Mallah, Helene Bolvin
    Abstract:

    : Two series of lanthanide complexes have been chosen to analyze trends in the magnetic properties and crystal field parameters (CFPs) along the two series: The highly symmetric LnZn16 (picHA)16 series (Ln=Tb, Dy, Ho, Er, Yb; picHA=picolinohydroxamic acid) and the [Ln(dpa)3 ](C3 H5 N2 )3 ⋅3H2 O series (Ln=Ce-Yb; dpa=2,6-dipicolinic acid) with approximate three-fold symmetry. The first series presents a compressed coordination sphere of eight oxygen atoms whereas in the second series, the coordination sphere consists of an elongated coordination sphere formed of six oxygen atoms. The CFPs have been deduced from ab initio calculations using two methods: The AILFT (ab initio ligand field theory) method, in which the parameters are determined at the orbital Level, and the ITO (irreducible tensor operator) decomposition, in which the problems are treated at the many-Electron Level. It has been found that the CFPs are transferable from one derivative to another, within a given series, as a first approximation. The sign of the second-order parameter B02 differs in the two series, reflecting the different environments. It has been found that the use of the strength parameter S allows for an easy comparison between complexes. Furthermore, in both series, the parameters have been found to decrease in magnitude along the series, and this decrease is attributed to covalent effects.

Julie Jung - One of the best experts on this subject based on the ideXlab platform.

  • Derivation of Lanthanide Series Crystal Field Parameters From First Principles
    Chemistry - A European Journal, 2019
    Co-Authors: Julie Jung, Claude Berthon, Talal Mallah, M. Ashraful Islam, Vincent Pecoraro, Helene Bolvin
    Abstract:

    Two series of lanthanide complexes have been cho- sen to analyze trends in the magnetic properties and crystal field parameters (CFPs) along the se- ries: the highly symmetric LnZn 16 (picHA) 16 series with Ln = Tb, Dy, Ho, Er, Yb and picHA=picoline hydroxamic, and the [Ln(DPA)3 ](C3H5N2)3·3H2O series with DPA = 2,6-dipicolinic acid and Ln = Ce–Yb and with approximate three-fold symmetry. The first series presents a compressed coordination sphere of 8 oxygen atoms environment while in the 2nd series, the coordination sphere is formed by an elongated coordination sphere formed by six oxy- gen atoms. CFPs are deduced from ab initio cal- culations using two methods: the AILFT (Ab Ini- tio Ligand Field Theory) which determines the pa- rameters at the orbital Level, and the ITO (Irre- ducible Technique Operator) decomposition which treats the problem at the many-Electron Level. It is shown that the CFPs are transferable from one derivative to the other, within a given series, as a first approximation. The sign of the 2nd order pa- rameter B02 differs in the two series reflecting the different environments. It is shown that the use of strength parameter S allows for an easy com- parison between complexes. Furthermore, in both series, the parameters are found to decrease in mag- nitude along the series and this decrease is imputed

  • derivation of lanthanide series crystal field parameters from first principles
    Chemistry: A European Journal, 2019
    Co-Authors: Julie Jung, Ashraful M Islam, Vincent L Pecoraro, Claude Berthon, Talal Mallah, Helene Bolvin
    Abstract:

    : Two series of lanthanide complexes have been chosen to analyze trends in the magnetic properties and crystal field parameters (CFPs) along the two series: The highly symmetric LnZn16 (picHA)16 series (Ln=Tb, Dy, Ho, Er, Yb; picHA=picolinohydroxamic acid) and the [Ln(dpa)3 ](C3 H5 N2 )3 ⋅3H2 O series (Ln=Ce-Yb; dpa=2,6-dipicolinic acid) with approximate three-fold symmetry. The first series presents a compressed coordination sphere of eight oxygen atoms whereas in the second series, the coordination sphere consists of an elongated coordination sphere formed of six oxygen atoms. The CFPs have been deduced from ab initio calculations using two methods: The AILFT (ab initio ligand field theory) method, in which the parameters are determined at the orbital Level, and the ITO (irreducible tensor operator) decomposition, in which the problems are treated at the many-Electron Level. It has been found that the CFPs are transferable from one derivative to another, within a given series, as a first approximation. The sign of the second-order parameter B02 differs in the two series, reflecting the different environments. It has been found that the use of the strength parameter S allows for an easy comparison between complexes. Furthermore, in both series, the parameters have been found to decrease in magnitude along the series, and this decrease is attributed to covalent effects.

Talal Mallah - One of the best experts on this subject based on the ideXlab platform.

  • Derivation of Lanthanide Series Crystal Field Parameters From First Principles
    Chemistry - A European Journal, 2019
    Co-Authors: Julie Jung, Claude Berthon, Talal Mallah, M. Ashraful Islam, Vincent Pecoraro, Helene Bolvin
    Abstract:

    Two series of lanthanide complexes have been cho- sen to analyze trends in the magnetic properties and crystal field parameters (CFPs) along the se- ries: the highly symmetric LnZn 16 (picHA) 16 series with Ln = Tb, Dy, Ho, Er, Yb and picHA=picoline hydroxamic, and the [Ln(DPA)3 ](C3H5N2)3·3H2O series with DPA = 2,6-dipicolinic acid and Ln = Ce–Yb and with approximate three-fold symmetry. The first series presents a compressed coordination sphere of 8 oxygen atoms environment while in the 2nd series, the coordination sphere is formed by an elongated coordination sphere formed by six oxy- gen atoms. CFPs are deduced from ab initio cal- culations using two methods: the AILFT (Ab Ini- tio Ligand Field Theory) which determines the pa- rameters at the orbital Level, and the ITO (Irre- ducible Technique Operator) decomposition which treats the problem at the many-Electron Level. It is shown that the CFPs are transferable from one derivative to the other, within a given series, as a first approximation. The sign of the 2nd order pa- rameter B02 differs in the two series reflecting the different environments. It is shown that the use of strength parameter S allows for an easy com- parison between complexes. Furthermore, in both series, the parameters are found to decrease in mag- nitude along the series and this decrease is imputed

  • derivation of lanthanide series crystal field parameters from first principles
    Chemistry: A European Journal, 2019
    Co-Authors: Julie Jung, Ashraful M Islam, Vincent L Pecoraro, Claude Berthon, Talal Mallah, Helene Bolvin
    Abstract:

    : Two series of lanthanide complexes have been chosen to analyze trends in the magnetic properties and crystal field parameters (CFPs) along the two series: The highly symmetric LnZn16 (picHA)16 series (Ln=Tb, Dy, Ho, Er, Yb; picHA=picolinohydroxamic acid) and the [Ln(dpa)3 ](C3 H5 N2 )3 ⋅3H2 O series (Ln=Ce-Yb; dpa=2,6-dipicolinic acid) with approximate three-fold symmetry. The first series presents a compressed coordination sphere of eight oxygen atoms whereas in the second series, the coordination sphere consists of an elongated coordination sphere formed of six oxygen atoms. The CFPs have been deduced from ab initio calculations using two methods: The AILFT (ab initio ligand field theory) method, in which the parameters are determined at the orbital Level, and the ITO (irreducible tensor operator) decomposition, in which the problems are treated at the many-Electron Level. It has been found that the CFPs are transferable from one derivative to another, within a given series, as a first approximation. The sign of the second-order parameter B02 differs in the two series, reflecting the different environments. It has been found that the use of the strength parameter S allows for an easy comparison between complexes. Furthermore, in both series, the parameters have been found to decrease in magnitude along the series, and this decrease is attributed to covalent effects.

Claude Berthon - One of the best experts on this subject based on the ideXlab platform.

  • Derivation of Lanthanide Series Crystal Field Parameters From First Principles
    Chemistry - A European Journal, 2019
    Co-Authors: Julie Jung, Claude Berthon, Talal Mallah, M. Ashraful Islam, Vincent Pecoraro, Helene Bolvin
    Abstract:

    Two series of lanthanide complexes have been cho- sen to analyze trends in the magnetic properties and crystal field parameters (CFPs) along the se- ries: the highly symmetric LnZn 16 (picHA) 16 series with Ln = Tb, Dy, Ho, Er, Yb and picHA=picoline hydroxamic, and the [Ln(DPA)3 ](C3H5N2)3·3H2O series with DPA = 2,6-dipicolinic acid and Ln = Ce–Yb and with approximate three-fold symmetry. The first series presents a compressed coordination sphere of 8 oxygen atoms environment while in the 2nd series, the coordination sphere is formed by an elongated coordination sphere formed by six oxy- gen atoms. CFPs are deduced from ab initio cal- culations using two methods: the AILFT (Ab Ini- tio Ligand Field Theory) which determines the pa- rameters at the orbital Level, and the ITO (Irre- ducible Technique Operator) decomposition which treats the problem at the many-Electron Level. It is shown that the CFPs are transferable from one derivative to the other, within a given series, as a first approximation. The sign of the 2nd order pa- rameter B02 differs in the two series reflecting the different environments. It is shown that the use of strength parameter S allows for an easy com- parison between complexes. Furthermore, in both series, the parameters are found to decrease in mag- nitude along the series and this decrease is imputed

  • derivation of lanthanide series crystal field parameters from first principles
    Chemistry: A European Journal, 2019
    Co-Authors: Julie Jung, Ashraful M Islam, Vincent L Pecoraro, Claude Berthon, Talal Mallah, Helene Bolvin
    Abstract:

    : Two series of lanthanide complexes have been chosen to analyze trends in the magnetic properties and crystal field parameters (CFPs) along the two series: The highly symmetric LnZn16 (picHA)16 series (Ln=Tb, Dy, Ho, Er, Yb; picHA=picolinohydroxamic acid) and the [Ln(dpa)3 ](C3 H5 N2 )3 ⋅3H2 O series (Ln=Ce-Yb; dpa=2,6-dipicolinic acid) with approximate three-fold symmetry. The first series presents a compressed coordination sphere of eight oxygen atoms whereas in the second series, the coordination sphere consists of an elongated coordination sphere formed of six oxygen atoms. The CFPs have been deduced from ab initio calculations using two methods: The AILFT (ab initio ligand field theory) method, in which the parameters are determined at the orbital Level, and the ITO (irreducible tensor operator) decomposition, in which the problems are treated at the many-Electron Level. It has been found that the CFPs are transferable from one derivative to another, within a given series, as a first approximation. The sign of the second-order parameter B02 differs in the two series, reflecting the different environments. It has been found that the use of the strength parameter S allows for an easy comparison between complexes. Furthermore, in both series, the parameters have been found to decrease in magnitude along the series, and this decrease is attributed to covalent effects.

K S Novoselov - One of the best experts on this subject based on the ideXlab platform.

  • large tunable valley splitting in edge free graphene quantum dots on boron nitride
    Nature Nanotechnology, 2018
    Co-Authors: Nils M Freitag, Tobias Reisch, Larisa A Chizhova, Peter Nemesincze, Christian Holl, Colin R Woods, R V Gorbachev, Yang Cao, A K Geim, K S Novoselov
    Abstract:

    Coherent manipulation of the binary degrees of freedom is at the heart of modern quantum technologies. Graphene offers two binary degrees: the Electron spin and the valley. Efficient spin control has been demonstrated in many solid-state systems, whereas exploitation of the valley has only recently been started, albeit without control at the single-Electron Level. Here, we show that van der Waals stacking of graphene onto hexagonal boron nitride offers a natural platform for valley control. We use a graphene quantum dot induced by the tip of a scanning tunnelling microscope and demonstrate valley splitting that is tunable from −5 to +10 meV (including valley inversion) by sub-10-nm displacements of the quantum dot position. This boosts the range of controlled valley splitting by about one order of magnitude. The tunable inversion of spin and valley states should enable coherent superposition of these degrees of freedom as a first step towards graphene-based qubits. The valley splitting in a stack of graphene and boron nitride can be controlled through a quantum dot induced by a scanning tunnelling microscope.

  • large tunable valley splitting in edge free graphene quantum dots on boron nitride
    arXiv: Mesoscale and Nanoscale Physics, 2017
    Co-Authors: Nils M Freitag, Tobias Reisch, Larisa A Chizhova, Peter Nemesincze, Christian Holl, Colin R Woods, R V Gorbachev, Yang Cao, A K Geim, K S Novoselov
    Abstract:

    Coherent manipulation of binary degrees of freedom is at the heart of modern quantum technologies. Graphene offers two binary degrees: the Electron spin and the valley. Efficient spin control has been demonstrated in many solid state systems, while exploitation of the valley has only recently been started, yet without control on the single Electron Level. Here, we show that van-der Waals stacking of graphene onto hexagonal boron nitride offers a natural platform for valley control. We use a graphene quantum dot induced by the tip of a scanning tunneling microscope and demonstrate valley splitting that is tunable from -5 to +10 meV (including valley inversion) by sub-10-nm displacements of the quantum dot position. This boosts the range of controlled valley splitting by about one order of magnitude. The tunable inversion of spin and valley states should enable coherent superposition of these degrees of freedom as a first step towards graphene-based qubits.