Preface
vii
The characteristic point of this effect is that the magnetic flux density B and vector
potential A are parallel to each other in the static force-free state. That is, the static
magnetic helicity is not zero in this state. This can be achieved only in superconductors with zero electrical resistivity. When Maxwell’s theory was completed in
the 19th century, superconductors had not been discovered. Hence, the state with
nonzero static magnetic helicity was not considered during the process of completion of Maxwell’s theory. In addition, such a peculiar state has not been theoretically
investigated from the viewpoint of electromagnetism. Hence, it is expected that we
can open a new pathway to unknown physics through investigating the peculiar electromagnetic phenomena in superconductors. One of these new phenomena is the
appearance of a magnetic generalized force, i.e., a torque, in spite of zero Lorentz
force. That is, the driving torque on flux lines is not equal to the moment of the
Lorentz force. The appearance of torque in the condition of no force cannot happen
in dynamics.
The characteristic points of electromagnetic phenomena in superconductors are
briefly introduced here. First, it is shown in this book not only that the diamagnetism
in the superconductors harmonizes with Maxwell’s theory, which was completed
before its discovery, but also that the dominant E-B analogy in the present electromagnetism loses perfection without the superconductor. Secondly, it is shown that
the flux pinning that brings about the beneficial feature of non-dissipative current in
DC condition causes special irreversibility in the AC condition. We have proved only
experimentally that if there is no energy dissipation in the superconductor caused by
the breaking of time reversal symmetry, it contradicts the thermodynamic principle
on energy conservation. This is now proved theoretically based on Maxwell’s theory,
since the irreversibility in the superconductor is theoretically derived. Thirdly, the
longitudinal magnetic field effect that is only known to a small number of researchers
is introduced, and it is shown that this phenomenon leads to a new development of
Maxwell’s theory. Thus, the electromagnetic phenomena in the superconductor are
deeply associated with electromagnetism over a wide range from the primary level
to new profound matters. The validity of Maxwell’s theory for all of them will be
clarified in this book.
This book will be recommended to people who are interested in science, especially
in superconductivity. It seems to be enough to read Chaps. 1–3 to gain knowledge
over a wide area. If the relationship with other related phenomena such as friction
or the application of superconductors in the future is interesting, Chap. 7 will also
be useful.
All of this book is recommended as an introduction to students or young scientists
who are interested in applied superconductivity, especially in power applications.
Then, if they are interested in practical electromagnetic phenomena such as flux
pinning mechanisms and flux creep in superconductors, it is desirable to move to
more technical books.
Many appendices will help the readers to understand the methods of derivation
of the equations. These will also be useful to clarify this particular way of thinking.
vii
The characteristic point of this effect is that the magnetic flux density B and vector
potential A are parallel to each other in the static force-free state. That is, the static
magnetic helicity is not zero in this state. This can be achieved only in superconductors with zero electrical resistivity. When Maxwell’s theory was completed in
the 19th century, superconductors had not been discovered. Hence, the state with
nonzero static magnetic helicity was not considered during the process of completion of Maxwell’s theory. In addition, such a peculiar state has not been theoretically
investigated from the viewpoint of electromagnetism. Hence, it is expected that we
can open a new pathway to unknown physics through investigating the peculiar electromagnetic phenomena in superconductors. One of these new phenomena is the
appearance of a magnetic generalized force, i.e., a torque, in spite of zero Lorentz
force. That is, the driving torque on flux lines is not equal to the moment of the
Lorentz force. The appearance of torque in the condition of no force cannot happen
in dynamics.
The characteristic points of electromagnetic phenomena in superconductors are
briefly introduced here. First, it is shown in this book not only that the diamagnetism
in the superconductors harmonizes with Maxwell’s theory, which was completed
before its discovery, but also that the dominant E-B analogy in the present electromagnetism loses perfection without the superconductor. Secondly, it is shown that
the flux pinning that brings about the beneficial feature of non-dissipative current in
DC condition causes special irreversibility in the AC condition. We have proved only
experimentally that if there is no energy dissipation in the superconductor caused by
the breaking of time reversal symmetry, it contradicts the thermodynamic principle
on energy conservation. This is now proved theoretically based on Maxwell’s theory,
since the irreversibility in the superconductor is theoretically derived. Thirdly, the
longitudinal magnetic field effect that is only known to a small number of researchers
is introduced, and it is shown that this phenomenon leads to a new development of
Maxwell’s theory. Thus, the electromagnetic phenomena in the superconductor are
deeply associated with electromagnetism over a wide range from the primary level
to new profound matters. The validity of Maxwell’s theory for all of them will be
clarified in this book.
This book will be recommended to people who are interested in science, especially
in superconductivity. It seems to be enough to read Chaps. 1–3 to gain knowledge
over a wide area. If the relationship with other related phenomena such as friction
or the application of superconductors in the future is interesting, Chap. 7 will also
be useful.
All of this book is recommended as an introduction to students or young scientists
who are interested in applied superconductivity, especially in power applications.
Then, if they are interested in practical electromagnetic phenomena such as flux
pinning mechanisms and flux creep in superconductors, it is desirable to move to
more technical books.
Many appendices will help the readers to understand the methods of derivation
of the equations. These will also be useful to clarify this particular way of thinking.