Implement constructor function for alternating layer ansatz

[ducthanh1991]

Hello,

Have you considered implementing a function to construct the alternating layer ansatz defined in the papers of Nakaji et al. and Cerezo et al. that would be similar to the existing hea function of the module qadence.constructors.ansatze?

[chMoussa]

Hi @ducthanh1991, we have not considered until you asked. It is probably a matter of changing slightly the support where a layer is applied with modulo repetitions, right?

[ducthanh1991]

Hello @chMoussa,

Yes, I guess that one would need to specify all the same parameters as for the hea function plus one additional parameter for the size of the support of the "local" block in the alternating layer ansatz.

something like:

ansatz = alt_digital(
        depth=`4,
        n_qubits=12,
        m_qubits_block=4,
        operations=[RX],
        entangler=CNOT,
        )
display(ansatz,size="15,15")

would yield:

[chMoussa]

Hello @chMoussa,

Yes, I guess that one would need to specify all the same parameters as for the hea function plus one additional parameter for the size of the support of the "local" block in the alternating layer ansatz.

something like:

ansatz = alt_digital(
        depth=`4,
        n_qubits=12,
        m_qubits_block=4,
        operations=[RX],
        entangler=CNOT,
        )
display(ansatz,size="15,15")

would yield:

Ok I will see what is possible to do with the current implementation, unless you already have something on your side?

[ducthanh1991]

Hello @chMoussa,

Yes I do have something that I wrote. I'll work on it during the weekend and make a pull request.

[ducthanh1991]

Hi @chMoussa,

I have created the pull request #565. Could you take a look?

[chMoussa]

Closes with #565