Authenticated quantum dialogue protocol based on four-particle entangled states

Many protocols of quantum dialogue are based on the assumption that the user is legitimate. In fact, the assumption is ideal. Therefore, it is necessary to identify whether the user is legitimate or not. In this paper, by adding identity authentication, a quantum dialogue protocol is proposed based on four-particle entangled states. For preparing the entangled state, we first give the description of the preparation process and draw the diagram of the prepared quantum circuit. Next, the nonlocal correlation properties of the entangled state are investigated. By associating identity authentication with channel security detection, the consumption of quantum resources is reduced to a certain extent. Furthermore, a random number r and a one-way hash function are added to increase the security of the protocol. In the end, compared with other protocols, our protocol has an improvement in efficiency.

Quantum Features of Atom–Field Systems in the Framework of Deformed Fields

We propose a new kind of Schrödinger cat state introduced as a superposition of spin coherent states in the framework of noncommutative spaces. We analyze the nonclassical features for these noncommutative deformed states in terms of the main physical parameters. The physical importance of deformed states is that they provide a convenient description of a large set of laser systems. As an application, we develop the Jaynes–Cummings model by considering the interaction among atoms and cat state fields associated to deformed spin algebras. In this context, we show the dynamical behavior of the nonlocal correlation and nonclassical properties in these quantum systems.

Emergent solidity of amorphous materials as a consequence of mechanical self-organisation

Amorphous solids have peculiar properties distinct from crystals. One of the most fundamental mysteries is the emergence of solidity in such nonequilibrium, disordered state without the protection by long-range translational order. A jammed system at zero temperature, although marginally stable, has solidity stemming from the space-spanning force network, which gives rise to the long-range stress correlation. Here, we show that such nonlocal correlation already appears at the nonequilibrium glass transition upon cooling. This is surprising since we also find that the system suffers from giant anharmonic fluctuations originated from the fractal-like potential energy landscape. We reveal that it is the percolation of the force-bearing network that allows long-range stress transmission even under such circumstance. Thus, the emergent solidity of amorphous materials is a consequence of nontrivial self-organisation of the disordered mechanical architecture. Our findings point to the significance of understanding amorphous solids and nonequilibrium glass transition from a mechanical perspective.