multiplet approach or with the monoelectronic DFT approach up to a brief survey
of the many-body extended theories. The second part is dedicated to the angular
dependence of electric dipole, E1:E1 and electric quadrupole E2:E2 terms, present
in the X-ray absorption cross sections where the emphasis is brought to their tensor
expansions. Various symmetries are considered, either octahedral or tetrahedral, as
well as the presence of an external or molecular magnetic field along with the
directions of high symmetry. The presentation is exhaustive but for the absence
of the crossed-terms necessary for the calculation of X-ray natural circular
dichroism and X-ray magneto-chiral dichroism.
Chapter 2, “Concepts in magnetism”, is a nice and concise introduction to
magnetism, necessary to make the present book a self-contained piece of work. The
basic, theoretical framework is presented so that spectroscopists with no knowledge
of magnetism can grasp the general picture. A special attention is devoted to the
role played by the orbital part in the building of the magnetic properties. This
emphasis needs to be acknowledged because the X-ray/matter interaction can be
fully described in the electric dipole and electric quadrupole approximations, where
no spin variables are present, so that X-ray absorption can be highly sensitive to the
orbital part of the electron wave function and more specifically to the orbital
magnetic moment.
Chapters 5 and 6 are descriptions of special states of matter where chemists and
physicists are tailoring matter so that it presents original, unprecedented characteristics. In the first part of Chap. 5, “Spintronics and synchrotron radiation”, the
authors give an overall view of the concept of magnetoresistance and they explore
how magnetization can be triggered in the absence of an external magnetic field,
with a special note on spin-orbitronics and the fascinating skyrmions. Then the
authors present the information that can be gained by advanced X-ray spectroscopies such as angle-resolved photoemission spectroscopy, X-ray magnetic circular dichroism and scanning transmission X-ray microscopy. In Chap. 6, “p-wave
superconductivity and d-vector representation”, the author presents advanced
concepts in the field of superconductivity. Through a special attention paid to the
role played by the orbital part of the electrons responsible for superconductivity, the
reader can make a connection with the information that can be extracted from
advanced, polarized X-ray spectroscopies.
Paris, France
Ph. Sainctavit
Foreword
ix
of the many-body extended theories. The second part is dedicated to the angular
dependence of electric dipole, E1:E1 and electric quadrupole E2:E2 terms, present
in the X-ray absorption cross sections where the emphasis is brought to their tensor
expansions. Various symmetries are considered, either octahedral or tetrahedral, as
well as the presence of an external or molecular magnetic field along with the
directions of high symmetry. The presentation is exhaustive but for the absence
of the crossed-terms necessary for the calculation of X-ray natural circular
dichroism and X-ray magneto-chiral dichroism.
Chapter 2, “Concepts in magnetism”, is a nice and concise introduction to
magnetism, necessary to make the present book a self-contained piece of work. The
basic, theoretical framework is presented so that spectroscopists with no knowledge
of magnetism can grasp the general picture. A special attention is devoted to the
role played by the orbital part in the building of the magnetic properties. This
emphasis needs to be acknowledged because the X-ray/matter interaction can be
fully described in the electric dipole and electric quadrupole approximations, where
no spin variables are present, so that X-ray absorption can be highly sensitive to the
orbital part of the electron wave function and more specifically to the orbital
magnetic moment.
Chapters 5 and 6 are descriptions of special states of matter where chemists and
physicists are tailoring matter so that it presents original, unprecedented characteristics. In the first part of Chap. 5, “Spintronics and synchrotron radiation”, the
authors give an overall view of the concept of magnetoresistance and they explore
how magnetization can be triggered in the absence of an external magnetic field,
with a special note on spin-orbitronics and the fascinating skyrmions. Then the
authors present the information that can be gained by advanced X-ray spectroscopies such as angle-resolved photoemission spectroscopy, X-ray magnetic circular dichroism and scanning transmission X-ray microscopy. In Chap. 6, “p-wave
superconductivity and d-vector representation”, the author presents advanced
concepts in the field of superconductivity. Through a special attention paid to the
role played by the orbital part of the electrons responsible for superconductivity, the
reader can make a connection with the information that can be extracted from
advanced, polarized X-ray spectroscopies.
Paris, France
Ph. Sainctavit
Foreword
ix