Because the subject of relativistic quantum field theory (QFT) contains all of non-relativistic quantum mechanics, we expect quantum field computation to contain (non-relativistic) quantum computation. Although we do not yet have a quantum theory of the gravitational field, and are far from a practical implementation of a quantum field computer, some pieces of the puzzle (without gravity) are n...

A free quantum field and its canonical conjugate are equivalent to a family of harmonic oscillators (one oscillator for each plane wave), which is in turn equivalent to a quantum theory of free identical bosons. In this note, I will show how all of this works for the relativistic scalar field φ̂(x) and its conjugate π̂(x). And then I will turn around and show that a quantum theory of any kind of ...

A free quantum field and its canonical conjugate are equivalent to a family of harmonic oscillators (one oscillator for each plane wave), which is in turn equivalent to a quantum theory of free identical bosons. In this note, I will show how all of this works for the relativistic scalar field φ̂(x) and its conjugate π̂(x). And then I will turn around and show that a quantum theory of any kind of ...

A free quantum field and its canonical conjugate are equivalent to a family of harmonic oscillators (one oscillator for each plane wave), which is in turn equivalent to a quantum theory of free identical bosons. In this note, I will show how all of this works for the relativistic scalar field φ̂(x) and its conjugate π̂(x). And then I will turn around and show that a quantum theory of any kind of ...

On the basis of the correspondence principle between the relativistic moving medium electrodynamics and relativistic quantum field theory the covari-ant Lagrangian of the electromagnetic field interaction with the polarized spin particles have been obtained. This Lagrangian satisfies the main relativistic quantum field theory requirements and contains four independent covariant spin structures,...

We study quantum field models in indefinite metric. We introduce the modified Wightman axioms of Morchio and Strocchi as a general framework of indefinite metric quantum field theory (QFT) and present concrete interacting relativistic models obtained by analytical continuation from some stochastic processes with Euclidean invariance. As a first step towards scattering theory in indefinite metri...

We present a framework for relativistic quantum metrology that is useful for both Earth-based and space-based technologies. Quantum metrology has been so far successfully applied to design precision instruments such as clocks and sensors which outperform classical devices by exploiting quantum properties. There are advanced plans to implement these and other quantum technologies in space, for i...

1 Quantum Field Theory ( QFT ) Why We Need It? 7 1.1 Two Flavors of QFT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1.2 QFT as a Special Application of Quantum Mechanics . . . . . . . . . . . . . 8 1.3 QFT as a Fundamentally New Physics Relativistic Multiparticle Quantum Physics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 1.3.1 QFT as conven...