Quantum fluctuations and disorder in superconducting arrays

김진우

Devin Underwood, Will Shanks, Jens Koch +1 more

To ultimately study phase transitions of light, arrays of superconducting resonators must be made with low disorder in individual resonator frequencies. We fabricate and measure such arrays, minimizing disorder to a few parts in 104.

Андрей Георгиевич Семенов, Andrei D. Zaikin

Андрей Георгиевич Семенов, Andrei D. Zaikin

Song Yang, Abolfazl Bayat, Sougato Bose

Quantum dot arrays are a promising medium for transferring quantum information between two distant points without resorting to mobile qubits. Here we study the two most common disorders, namely hyperfine interaction and exchange coupling fluctuations, in quantum dot arrays and their effects on quantum communication through these chains. Our results show that the hyperfine interaction is more destructive than the exchange coupling fluctuations. The average optimal time for communication is not affected by any disorder in the system and our simulations show that antiferromagnetic chains are much more resistive than the ferromagnetic ones against both kind of disorders. Even when time modulation of a coupling and optimal control is employed to improve the transmission, the antiferromagnetic chain performs much better. We have assumed the quasistatic approximation for hyperfine interaction and time-dependent fluctuations in the exchange couplings. Particularly for studying exchange coupling fluctuations we have considered the static disorder, white noise, and $1/f$ noise.

Wang Wenguo, MANFRED L. RISTIG