Evolving_War

 Le Monde publishes an ongoing overview of the situation in Ukraine. Below,

Feb 24, 2022:

                                                                  

Nov 10, 2024:

                                                                               

Invasion de l’Ukraine en cartes : l’évolution des combats semaine après semaine

*     *     *

On the quantum computing side, it's been a journey trying to learn how to use

the Estimator primitive. I asked for 127 qubits, then 65, then 10 and finally settled for 3.

Thus,  ended up with what  I needed, which is a baseline construct which will allow me

to test the utility of the various error mitigations approaches. Below:

                                                                         

One can construct a circuit but one does not measure it (this would collapse things).

 One is looking for an expectation value...

ChatGPT 3.5

qiskit; is it correct to say that in using Estimator, one doesn’t measure things…

Yes, that’s correct. When using the Estimator in Qiskit, you are not performing traditional measurements in the same way that you would in a quantum circuit. Instead, you are estimating expectation values directly from the quantum state representations without collapsing the state through measurement.

Key Points about the Estimator:

Expectation Values Without Measurement:

The Estimator computes expectation values by simulating the process mathematically rather than actually performing physical measurements on qubits. This allows you to obtain theoretical outcomes based on the given quantum circuit and observable.

Qiskit Runtime:

The Estimator is part of the Qiskit Runtime framework and is designed to perform operations more efficiently by leveraging quantum hardware capabilities. It can calculate expected values from the circuits defined in your code.

No State Collapse:

Traditional quantum measurements collapse the quantum state to one of the basis states, which can affect subsequent computations. In contrast, the Estimator evaluates expected outcomes based on the entire quantum state, allowing for a more cohesive analysis of quantum dynamics.

Applications:

The Estimator is particularly useful for variational algorithms and scenarios where you need estimates of expectation values without the overhead of multiple measurements, such as in quantum simulations and optimization problems.

Conclusion

In summary, when using the Estimator in Qiskit, you're focused on calculating expectation values for observables based on the quantum circuits you've defined, rather than directly measuring the states of qubits in a way that would collapse them. This approach allows for a more holistic view of quantum behavior and is efficient for many applications.