On the robustness of the hybrid qubit computational gates through simulated randomized benchmarking protocols

Abstract

One of the main challenges in building a quantum processor is to characterize the environmental noise. Noise characterization can be achieved by exploiting different techniques, such as randomization where several sequences of random quantum gates are applied to the qubit under test to derive statistical characteristics about the affecting noises. A scalable and robust algorithm able to benchmark the full set of Clifford gates using randomization techniques is called randomized benchmarking. In this study, we simulated randomized benchmarking protocols in a semiconducting all-electrical three-electron double-quantum dot qubit, i.e. hybrid qubit, under different error models, that include quasi-static Gaussian and the more realistic 1/f noise model, for the input controls. The average error of specific quantum computational gates is extracted through interleaved randomized benchmarking obtained including Clifford gates between the gate of interest. It provides an estimate of the fidelity as well as theoretical bounds for the average error of the gate under test.

Silicon spin qubits from laboratory to industry

“…The hybrid qubit is a three spins qubit and owes its name to the fact that is an hybrid of spin and charge qubit [26,59]. It is realized in a DQD in which three electrons have been confined with all-electrical control via gate electrodes [60][61][62][63][64][65][66][67][68][69]. The logical states have been defined by adopting combined singlet and triplet states of a pair of electrons occupying one dot with the states of the single electron occupying the other and they are |0⟩ ≡ |S⟩| ↑⟩ and |1⟩ ≡ √…”

Parallel Gate Operations Fidelity in a Linear Array of Flip‐Flop Qubits

“…[11], the entanglement fidelity F [20] is calculated for each gate when the 1/f noise model on the electric field ΔE z is considered. [21][22][23][24][25][26] The entanglement fidelity is a figure of merit that does not depend on the initial condition chosen for the qubit and is given by…”

“…[11], the entanglement fidelity F [ 20 ] is calculated for each gate when the 1/f noise model on the electric field $$\Delta E_z$$ is considered. [ 21–26 ]…”

Universal set of quantum gates for the flip-flop qubit in the presence of 1/f noise

“…In this subsection we present the results obtained analyzing the entanglement fidelity for the single-qubit R z (− π 2 ) and H gates when the 1/f noise model is included [14,[17][18][19][20]. The 1/f noise model is based on the definition of the Power Spectral Density (PSD) that is inversely proportional to the frequency and is given by S(ω) = α/(ωt 0 ), where α is the noise amplitude, that does not depend on ω and t 0 is the time unit.…”

“…For both the quantum gates we observe the same qualitative behaviour of the infidelity. In the intervals α ∆Ez [1,20] V/m for R z (− π 2 ) and α ∆Ez [1,40] V/m for H, the infidelities show a plateau that reflects the nonadiabaticity of the sequence. Increasing the value of the coefficient K leads to a more adiabatic operation that returns a lower value of the infidelities in the plateau.…”