One important aspect of our universe is that one cannot get something from nothing; there is always a price to pay. In this article we show that every bit of information is limited by a quantum unit. Since we are communicating within a temporal subspace, this unit can be equivalently described as a quantum limited subspace (QLS), as imposed by the Heisenberg Principle. We show that communication can be exploited within and outside the QLS. The size of a QLS is determined by carrier signal bandwidth; that is narrower the bandwidth the larger the size of the QLS. By manipulating the size of a QLS, more efficient information transmission strategies can be developed. Examples for inside and outside QLS communication are given. Extension to relativistic communication has also demonstrated. We remark that, a new era of communication is anticipated to immerge and it will change our way in communicating, observation and computing, we used to use, forever!
Abstract One important aspect of our universe is that one cannot get something from nothing; there is always a price to pay. In this article we show that every bit of information is limited by a quantum unit. Since we are communicating within a temporal subspace, this unit can be equivalently described as a quantum limited subspace (QLS), as imposed by the Heisenberg Principle. We show that communication can be exploited within and outside the QLS. The size of a QLS is determined by carrier signal bandwidth; that is narrower the bandwidth the larger the size of the QLS. By manipulating the size of a QLS, more efficient information transmission strategies can be developed. Examples for inside and outside QLS communication are given. Extension to relativistic communication has also demonstrated. We remark that, a new era of communication is anticipated to immerge and it will change our way in communicating, observation and computing, we used to use, forever!
The majority of current understanding of the quantum correlations is in the field of non-relativistic quantum mechanics. To develop quantum information and computation tasks fully, one must inevitably take into account the relativistic effects. In this regard, the spin is one of the central tools. For this purpose, it is of paramount importance to understand and characterize fully the theory of spin in relativistic quantum information theory where the spin states act as qubit. This area is still far from being resolved. As a result, this article will explore the recent studies of the concepts of the spin and spin quantum correlations in inertial frames and some apparent paradoxes regarding this concept. We will mainly focus on the problem of characterizing the spin, reduced spin density matrices and spin quantum correlations in inertial reference frames and the apparent paradoxes involved therein. Another important aspect is the use of tools of quantum field theory to extend several concepts in non-relativistic domain to relativistic one. In this regard, we analyze the development of the theory of relativistic secret sharing and a correlation measure namely the entanglement of purification.