Related papers: No-cloning and superluminal signaling
A nonlinear extension of Schr\"odinger's wave equation is proposed that ensures non-signaling by keeping linear the evolution of \textit{coordinate-diagonal} elements of the density matrix. The equation contains a negative kinetic energy…
The possible existence of closed timelike curves (CTCs) draws attention to fundamental questions about what is physically possible and what is not. An example is the "no cloning theorem" in quantum mechanics, which states that no physical…
It is well known that it is impossible to clone an arbitrary quantum state. However, this inability does not lead directly to no-cloning of quantum coherence. Here, we show that it is impossible to clone the coherence of an arbitrary…
The quantum mechanical no-cloning theorem for pure states is generalized and transfered to the quantum logics with a conditional probability calculus in a rather abstract, though simple and basic fashion without relying on a tensor product…
Incompatibility is a feature of quantum theory that sets it apart from classical theory, and the inability to clone an unknown quantum state is one of the most fundamental instances. The no-hiding theorem is another such instance that…
No-cloning theorem is fundamental for quantum mechanics and for quantum information science that states an unknown quantum state cannot be cloned perfectly. However, we can try to clone a quantum state approximately with the optimal…
Metz et al PRL (83), 1542 (1999) have presented evidence for supersymmetry in atomic nuclei but their model Hamiltonian fails to distinguish between irreducible representations that occur with multiplicities greater than one. This failure…
Photonic tunneling permits superluminal signal transmission. The principle of causality is not violated but the time duration between cause and effect can be shortened compared with an interaction exchange with velocity of light. This…
We show that the superluminal muon neutrinos in the recent OPERA experiment can exist theoretically. The refutation of the OPERA experiment from some theoretical arguments is not universally valid, but resulting from some implicit…
Quantization of the nonlinear supersymmetry faces a problem of a quantum anomaly. For some classes of superpotentials, the integrals of motion admit the corrections guaranteeing the preservation of the nonlinear supersymmetry at the quantum…
Recently, Chen \em et al \rm.\ [Phys. Rev. A 84, 033835 (2011)] reported observation of anticorrelated photon coincidences in a Mach-Zehnder interferometer whose input light came from a mode-locked Ti:sapphire laser that had been rendered…
We believe that a recent, unconventional theoretical work published in Physical Review Letters 103, 113601 (2009) by Sekatsky, Brunner, Branciard, Gisin, Simon, albeit appealing at fist sight, is highly questionable. Furthermore, the…
After a brief introduction to the quantum no-cloning theorem and its link with the linearity and causality of quantum mechanics, the concept of quantum cloning machines is sketched, following, whenever possible, the chronology of the main…
It is sometimes claimed that Lorentz invariant wave equations which allow superluminal propagation exhibit worse predictability than subluminal equations. To investigate this, we study the Born-Infeld scalar in two spacetime dimensions.…
In 1981 N. Herbert proposed a gedanken experiment in order to achieve by the ''First Laser Amplified Superluminal Hookup'' (FLASH) a faster than light communication (FTL) by quantum nonlocality. The present work reports the first…
A physicists' explanation of why thou shalt not clone one bit gives a stronger version of Conway and Kochen's theorem.
The new results by OPERA collaboration claim the discovery of superluminal neutrinos. Superluminal particles have to break Lorentzian symmetry or causality principle. The method discussed gives us the possibility to reintroduce Lorentzian…
We discuss some properties of Lorentz invariant theories which allow for superluminal motion. We show that, if signals are always sent forward in time, closed curves along which signals propagate can be formed. This leads to problems with…
Two of the key properties of quantum physics are the no-signaling principle and the Grover search lower bound. That is, despite admitting stronger-than-classical correlations, quantum mechanics does not imply superluminal signaling, and…
We analyze the possibility of superluminal neutrino propagation delta v = (v - c)/c > 0 as indicated by OPERA data, in view of previous phenomenological constraints from supernova SN1987a and gravitational Cerenkov radiation. We argue that…