scholarly journals Quantum behavior of a dc SQUID phase qubit

2008 ◽  
Vol 77 (21) ◽  
Author(s):  
Kaushik Mitra ◽  
F. W. Strauch ◽  
C. J. Lobb ◽  
J. R. Anderson ◽  
F. C. Wellstood ◽  
...  
Keyword(s):  
Nanomaterials ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 73
Author(s):  
Marta I. Hernández ◽  
Massimiliano Bartolomei ◽  
José Campos-Martínez

We report accurate quantum calculations of the sieving of Helium atoms by two-dimensional (2D) graphtriyne layers with a new interaction potential. Thermal rate constants and permeances in an ample temperature range are computed and compared for both Helium isotopes. With a pore larger than graphdiyne, the most common member of the γ-graphyne family, it could be expected that the appearance of quantum effects were more limited. We find, however, a strong quantum behavior that can be attributed to the presence of selective adsorption resonances, with a pronounced effect in the low temperature regime. This effect leads to the appearance of some selectivity at very low temperatures and the possibility for the heavier isotope to cross the membrane more efficiently than the lighter, contrarily to what happened with graphdiyne membranes, where the sieving at low energy is predominantly ruled by quantum tunneling. The use of more approximate methods could be not advisable in these situations and prototypical transition state theory treatments might lead to large errors.


2012 ◽  
Vol 605-607 ◽  
pp. 2442-2446
Author(s):  
Xin Ran Li ◽  
Yan Xia Jin

The article puts forward an improved PSO algorithm based on the quantum behavior——CMQPSO algorithm to improve premature convergence problem in particle swarm algorithm. The new algorithm first adopts Tent mapping initialization of particle swarm, searches each particle chaos, and strengthens the diversity of searching. Secondly, a method of effective judgment of early stagnation is embedded in the algorithm. Once the early maturity is retrieved, the algorithm mutates particles to jump out of the local optimum particle according to the structure mutation so as to reduce invalid iteration. The calculation of classical function test shows that the improved algorithm is superior to classical PSO algorithm and quantum-behaved PSO algorithm.


2008 ◽  
Vol 10 (7) ◽  
pp. 073026 ◽  
Author(s):  
S N Shevchenko ◽  
A N Omelyanchouk ◽  
A M Zagoskin ◽  
S Savel'ev ◽  
Franco Nori
Keyword(s):  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Javad Sharifi

AbstractMicrowave IQ-mixer controllers are designed for the three approximated Hamiltonians of charge, phase and flux qubits and the controllers are exerted both on approximate and precise quantum system models. The controlled qubits are for the implementation of the two quantum-gates with these three fundamental types of qubits, Quantum NOT-gate and Hadamard-gate. In the charge-qubit, for implementation of both gates, in the approximated and precise model, we observed different controlled trajectories. But fortunately, applying the controller designed for the approximated system over the precise system leads to the passing of the quantum state from the desired state sooner that the expected time. Phase-qubit and flux qubit have similar behaviour under the control system action. In both of them, the implementation of NOT-gate operation led to same trajectories which arrive at final goal state at different times. But in both of those two qubits for implementation of Hadamard-gate, desired trajectory and precise trajectory have some angle of deviation, then by exerting the approximated design controller to precise system, it caused the quantum state to approach the goal state for Hadamard gate implementation, and since the quantum state does not completely reach the goal state, we can not obtain very high gate fidelity.


2018 ◽  
Vol 2018 (09) ◽  
pp. 031-031 ◽  
Author(s):  
Mariam Bouhmadi-López ◽  
David Brizuela ◽  
Iñaki Garay
Keyword(s):  
Big Rip ◽  

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