5. Quantum Hardware
Superconductingqubits — Quiz
Test your understanding of superconductingqubits with 5 practice questions.
Practice Questions
Question 1
What is the primary role of the cosine potential provided by the Josephson junction in a transmon qubit?
Question 2
Given a transmon with $E_J/h=25\,$GHz and $E_C/h=0.25\,$GHz, approximate the 0→1 transition frequency $f_{01}$ using $$f_{01}\approx\frac{\sqrt{8E_JE_C}}{h}-\frac{E_C}{h}\,.$$
Question 3
Which physical mechanism underlies the cross-resonance two-qubit gate in fixed-frequency transmon qubits?
Question 4
Which characteristic distinguishes a travelling-wave parametric amplifier (TWPA) from a lumped-element Josephson parametric amplifier (JPA)?
Question 5
During dispersive readout, increasing the average photon number in the readout resonator beyond its critical photon number primarily leads to which effect?