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What is a transmon qubit?
In quantum computing, and more specifically in superconducting quantum computing, a transmon is a type of superconducting charge qubit that was designed to have reduced sensitivity to charge noise.
What is type1 and type 2 superconductor?
A type I superconductor keeps out the whole magnetic field until a critical app- lied field Hc reached. A type II superconductor will only keep the whole magnetic field out until a first critical field Hc1 is reached. Then vortices start to appear. A vortex is a magnetic flux quantum that penetrates the superconductor.
What are the disadvantages of superconductors?
What are the disadvantages of superconductors?
- Low critical temperatures are difficult, expensive and energy intensive to maintain.
- The materials are usually brittle, not ductile and hard to shape.
- They are also chemically unstable in some environments.
How is a transmon different from a charge qubit?
This is one of the main differences: the transmon Hamiltonian (like the charge qubit Hamiltonian) is periodic in the flux basis while the flux qubit Hamiltonian is not periodic in the flux basis. The physical reason for this difference is that the transmon (and charge) qubit do not have a dc path to ground.
Is the Cooper pair box a two level system?
The Cooper Pair Box consists of a superconducting island that possesses an extra Cooper pair of charge 2e2e ( | 0⟩|0⟩) or does not ( | 1⟩|1⟩ ). These states can be manipulated by voltages on tunnel junctions, and is periodic with “gate” voltage control, so it is indeed a two-level system.
How is a transmon different from a capacitor?
The transmon is a Josephson junction and capacitor in parallel. Originally, transmons were differential circuits, i.e. two transmons on the same chip were not galvanically connected in any way. In other words, transmons didn’t share a ground reference.
What is the Hamiltonian of a transmon drive?
The Hamiltonian is the sum of the qubit Hamiltonian ˆH0 and drive Hamiltonian ˆHd, ˆH = ˆH0 + ˆHd. Treating the transmon as a qubit allows us to use the Pauli raising/lowering operators σ ± = (1 / 2)(σx ∓ iσy) that have the effect σ + | 0⟩ = | 1⟩ and σ + | 1⟩ = | 0⟩.