Ahmed Farouk

Modelling the spice parameters of SOI MOSFET using a combinational algorithm

Progress in the technology of submicron semiconductor device, which makes a short-channel and quantum effects, having equations of nonlinear modelling, leads to complicated and time-consuming calculations. In order to control these complexities and obtain the device characteristics according to device parameters, a faster method is needed. In this paper, a combinational algorithm is proposed for modelling a nano silicon-on-insulator metal–oxide–semiconductor field effect transistor (SOI MOSFET) characteristic. The proposed method shows the same device characteristics with lower input parameters. In this method, a combination of genetic algorithm (GA) and artificial neural network are used. Then quantum evolutionary algorithm (QEA) is employed instead of genetic algorithm (GA) for comparing and modifying algorithm. Results show that the algorithm’s accuracy is 95% and 98% for test data of GA and QGA, respectively. Moreover, the reduction percentage of input parameters are 11% and 52% for GA and QEA, respectively. The simulation results represent that the implemented quantum genetic algorithm for prediction of device characteristics is more effective and accurate than GA.

New quantum dialogue protocol based on continuous-variable two-mode squeezed vacuum states

A new quantum dialogue protocol is designed by using the continuous-variable two-mode squeezed vacuum states due to its entanglement property. The two communication parties encode their own secret information into the entangled optical modes with the translation operations. Each communication party could deduce the secret information of their counterparts with the help of his or her secret information and the Bell-basis measurement results. The security of the proposed quantum dialogue protocol is guaranteed by the correlation between two-mode squeezed vacuum states and the decoy states performed with translation operations in randomly selected time slots. Compared with the discrete variable quantum dialogue protocols, the proposed continuous-variable quantum dialogue protocol is easy to realize with perfect utilization of quantum bits.

Secret sharing of a known arbitrary quantum state with noisy environment

We study quantum state sharing (QSTS) with noisy environment in this paper. As an example, we present a QSTS scheme of a known state whose information is hold by the dealer and then investigate the noisy influence process of the scheme. Taking the amplitude-damping noise and the phase-damping noise as typical noisy channels, we show that the secret state can be shared among agents with some information lost. Our research connects the areas of quantum state sharing and remote state preparation.

A generalized architecture of quantum secure direct communication for N disjointed users with authentication.

In this paper, we generalize a secured direct communication process between N users with partial and full cooperation of quantum server. So, N − 1 disjointed users u1, u2, …, uN−1 can transmit a secret message of classical bits to a remote user uN by utilizing the property of dense coding and Pauli unitary transformations. The authentication process between the quantum server and the users are validated by EPR entangled pair and CNOT gate. Afterwards, the remained EPR will generate shared GHZ states which are used for directly transmitting the secret message. The partial cooperation process indicates that N − 1 users can transmit a secret message directly to a remote user uN through a quantum channel. Furthermore, N − 1 users and a remote user uN can communicate without an established quantum channel among them by a full cooperation process. The security analysis of authentication and communication processes against many types of attacks proved that the attacker cannot gain any information during intercepting either authentication or communication processes. Hence, the security of transmitted message among N users is ensured as the attacker introduces an error probability irrespective of the sequence of measurement.

A scheme for secure quantum communication network with authentication using GHZ-like states and cluster states controlled teleportation

We propose a scheme for a secure message communication network with authentication following the idea in controlled teleportation. In this scheme, the servers of the network provide the service to prepare the entangled states as quantum channels. For preventing the eavesdropping, a security checking method is suggested. After the security check, any two users in the network may communicate securely and directly under the control of the servers on the network.

Do multipartite correlations speed up adiabatic quantum computation or quantum annealing

Quantum correlations are thought to be the reason why certain quantum algorithms overcome their classical counterparts. Since the nature of this resource is still not fully understood, we shall investigate how multipartite entanglement and non-locality among qubits vary as the quantum computation runs. We shall encounter that quantum measures on the whole system cannot account for their corresponding speedup.

Nonlocality in pure and mixed n-qubit X states

Nonlocality for general multiqubit X states is studied in detail. Pure and mixed states are analyzed as far as their maximum amount of nonlocality is concerned, and analytic results are obtained for important families of these states. The particular form of nonzero diagonal and antidiagonal matrix elements makes the corresponding study easy enough to obtain exact results. We also provide a numerical recipe to randomly generate an important family of X states endowed with a given degree of mixture.

Quantum information approach to the azurite mineral frustrated quantum magnet

Quantum correlations are almost impossible to address in bulk systems. Quantum measures extended only to a few number of parties can be discussed in practice. In the present work, we study nonlocality for a cluster of spins belonging to a mineral whose structure is that of a quantum magnet. We reproduce at a much smaller scale the experimental outcomes, and then, we study the role of quantum correlations there. A macroscopic entanglement witness has been introduced in order to reveal nonlocal quantum correlations between individual constituents of the azurite mineral at nonzero temperatures. The critical point beyond which entanglement is zero is found at

A New Quantum Watermarking Based on Quantum Wavelet Transforms

T_c < 1\,\mathrm{K}