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# Tag Info

### Why do the IBM and Google processors both have 53 qubits?

It's just a coincidence. I can speak from personal recollection on the Google side. Google originally intended to use a 72 qubit chip (Bristlecone) where qubits were essentially directly connected to ...
• 21.9k

### Topology graphs of IBM's quantum computers

The graph shows you how the physical qubits are connected together on the real device you will be using. For example, on the graph you put, qubit 0 has a physical connection to qubit 1 and qubit 14 on ...
• 2,334

### Why IBM devices have the same number of qubit and the same architecture, but the error rates are different?

They have different error rates because they are two different physical devices! This relates to the manufacturing processes of these chips. Every device is unique and will have its own fingerprint ...
• 502

### Would IBM's "compiler" turn my identity circuit into nothing?

Any compilation/circuit optimization happens transparently by Qiskit. As a user you have control over what happens via the optimization_level argument passed to <...
• 1,542
Accepted

• 46.3k
Accepted

### Is every computer in IBM's fleet based on superconductivity?

Yes. IBM uses superconducting Transmon qubit. Here is a quote from IBM's website: At the heart of IBM quantum systems is the transmon qubit. Successive generations of IBM Quantum processors have ...
• 12.3k

### Qiskit's c_if and conditioned operations on a real quantum computer

As far as I know, c_if operation is not implementable on IBM's hardware currently. But it should be implementable on simulator. For instance, if I tried to execute ...
• 12.3k

### Error 400 on submission request on job that ran before

This was due to temporary issue on IBM side. If you try to resubmit your job it should work as before.
• 116
Accepted

### Why is a 15-qubit IBM quantum computer not working correctly?

There will be a lot of swapping and additional gates during the execution of your circuit since CCX is not a native gate. The actual circuit that is being executed is something like: This circuit has ...
• 12.3k