Quantum Information in Gravitational Fields

This book offers a concise discussion of quantum information in classical gravitational fields described by Einstein's General Theory of Relativity. Besides a basic description of the fundamental physical principles of quantum fields in curved space-times, it also covers some new results on steganographic quantum communications in inertial frames, qubits in Schwarzschild space-time, spin-curvature coupling in Schwarzschild space-time, qubits in Kerr space-times, and the performance of quantum technologies operating in gravitational fields.

A significant part of Quantum Information in Gravitational Fields is restricted to qubits represented by spin-½ particles (e.g. electrons). The case of spin-1 particles (e.g. photons) will be covered in a subsequent book. Making strong emphasis on the smooth interplay between the physics and mathematics of general relativity and relativistic quantum mechanics, this book takes a unifying group-theoretic approach to these topics. Therefore, the description of relativistic spin-½ particles included are based on the representations of the Poincare group, while gravitational effects are introduced through Lorentz transformations in local inertial frames properly defined by tetrad fields. In particular, analysis shows how spin-½ qubits are affected by a stationary spherically symmetric gravitational field (Schwarzschild metric) and by a stationary axisymmetric gravitational field (Kerr metric). In addition, there is an example that shows the coupling between a qubit's spin and space-time curvature.

Finally, gravitational effects in the context of quantum communications, entanglement, EPR experiments, quantum computation and sensing as discussed.