mavzolej
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Exponentiating Pauli matrices using trapped ion native gates (single-qubit rotations + XX, YY, ZZ)
1 votes

The following answer to this question was given by Dmitrii Maslov in a private conversation. An improvement to the approach described in the original post can be made by noticing that the middle block ...

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Ansatz state for finding the lowest eigenvalue of a $2^n\times 2^n$ real matrix using VQE
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1 votes

For preparing an arbitrary $n$-qubit state with real amplitudes, you can simply: Take a circuit for preparing arbitrary states, Replace all single-qubits rotations with $R_y$ rotations. Here is how ...

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Jordan-Wigner $\leftrightarrow$ Bravyi-Kitaev transformation in Qiskit
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1 votes

I have not found such functionality in Qiskit. However, one can use the openfermion function openfermion.transforms._encoder_bk(): def _encoder_bk(n_modes): """ Helper function for ...

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Trotterizing a Pauli sum in Qiskit
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1 votes

Looks like this works: qc_trotter = paulistring.evolve( evo_time = 1, expansion_order = 2) where qc_trotter is an object of type WeightedPauliOperator, see here. ...

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Is there a separable state that is furthest away from an entangled one?
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A somewhat informal comment. Some intuition can be developed from the fact that the pure states are rays in the complex projective space (subject to an additional normalization constraint). The most ...

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What's the point of VQE if classical computers can solve for eigenvalues easily?
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6 votes

The computational advantage of using quantum computers can be reached if the classical resources (memory; number of operations), required to solve a particular problem, grow exponentially in a certain ...

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Matrix mod 2 multiplication
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3 votes

The answer to my question is given here. The solution from the provided paper is extremely efficient (for it requires $O(n^2 / \log n)$ CNOTs instead of the naïve $O(n^2)$ estimate), and is somewhat ...

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