Questions tagged [physical-qubit]

For questions related to physical realizations of quantum bits i.e. quantum systems living in a 2-dimensional Hilbert space.

15 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
5
votes
1answer
111 views

What design considerations set the frequency bounds for superconducting qubits?

Superconducting qubits generally have frequencies within the range of 4 - 8 GHz. What design considerations give the upper and lower bounds for what is a feasible design. I.e, why can't they be higher ...
4
votes
0answers
193 views

What is the charging energy in relation to a superconducting transmon?

The transmon achieves its reduced sensitivity to charge noise by significantly increasing the ratio of the Josephson energy to the charging energy. What is this charging energy?
3
votes
0answers
31 views

On the IBM-Q experience, how do different frequencies for different qubits affect results?

I've been looking at the graphs of various Quantum Processors on IBM-Q experience and for qubits, frequency of different qubits is the first statistic shown. From this in the Qiskit textbook: The ...
3
votes
1answer
28 views

What does a gate electrode do in the context of a quantum dot?

I am trying to understand the creation of qubits through the use of quantum dots, but I have always had some trouble understanding the function of the gate electrode. I know it can control the ...
3
votes
0answers
181 views

What is the difference between a cooper pair box and a transmon qubit?

These two kinds of qubits are both classified under "charge qubits", looking for them, I always find the same circuit representation. Occasionally, I find one where there's a SQUID instead of the ...
3
votes
0answers
38 views

Excitation of a superconducting circuit

What do we mean by exciting a superconducting circuit--which represent a qubit, how they are get excited inside? how the two states of the qubit are represented in this circuit?
3
votes
0answers
70 views

States of a qubit in a DC-SQUID

Does anybody of you know what are the two states $|0\rangle$ and $|1\rangle$ of a qubit in a DC-SQUID (2 Josephson junctions in a loop)?
3
votes
0answers
32 views

How much power do quantum computers use based on the number of qubits being allocated?

How much power do quantum computers use based on the number of qubits being allocated? If it's not based on qubits, What determines how much power quantum computers use? Note: A similar question was ...
3
votes
0answers
29 views

Can one make NV centred type qubits from analogus materials in the periodic table?

Can one replace Nitrogen with Phosphorus and Carbon with Silicon and so on? What would be the conditions that would preclude such a realisation? Are there any implemenations so far?
2
votes
0answers
52 views

I thought we had already passed this error and qubit threshold?

As outlined in Quantum Computing Progress and Prospects published this year, on page 169-171 there is the diagram showing that we are at the 10's of qubits mark. Looking into the diagram further there ...
2
votes
0answers
76 views

What noise channel that is not coming from the control can lead to XY qubit rotations?

In a semiclassical treatment, the noise Hamiltonian of a quantum system can be treated as a summation over its noise channels in the following way: $$\hat{H}_{\text{noise}}=\sum_{k}\beta_{k}\left(t\...
2
votes
0answers
21 views

Hamiltonian of the valence electron of Yb+ ion

Let's say I have chosen the valence electron of Yb+ as my qubit. I want to consider it's hyperfine structure as the two-level energy states. Are my following assumptions correct? If the magnetic ...
1
vote
0answers
48 views

How qubit phase is build in real hardware?

How qubit phase is build in real hardware? On IBM Quantum, D-Wave, etc?
1
vote
0answers
78 views

Charge Qubit vs Transmon

I want to know the big difference, in terms of fabrication (circuit) between a charge Qubit and a Transmon, how is a Transmon less affected by noise ? Many thanks
-3
votes
0answers
42 views

What is a qubit's impulse response?

As far as I know, qubits are primarily measured in the frequency domain, sending a relatively long, spectrually pure pulse to interrogate the qubit's state. In general, what would happen if you sent a ...