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4 votes

Solving quantum equation using qiskit

The paper is about the FABLE block encoding. One way to implement this in qiskit is by first using the classiq SDK package to build the model on the functional level, synthesize to a quantum program, ...
tomergf's user avatar
  • 121
3 votes

How to implement a quantum multiplier in Qiskit 1.0

I think that the problem is that you are passing a non-transpiled circuit to the job execution. I do not know why transpilation is not part of the run command. If ...
tomergf's user avatar
  • 121
3 votes
Accepted

Finding Eigenvectors of a Unitary in a Quantum circuit

You can simply use numpy: ...
Tristan Nemoz's user avatar
  • 6,712
3 votes
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Generating Equal Amplitude Superposition States from Another Equal Amplitude Superposition State

TL;DR Yes, it is actually very simple to prepare a state that has the wanted property. Namely, $$|i\rangle^{\otimes n} = S^{\otimes n} H^{\otimes n} |0\rangle^{\otimes n}$$ with $|i\rangle = \frac{1}{\...
qubitzer's user avatar
  • 577
2 votes

IBMBackendValueError: number of circuits exceeds the maximum for this backend, 300

I think you need to restrict the maximal number of function call by qml.AdamOptimizer(args.lr_qaoa) to be below 300, make it 290. Executing too many circuits on ...
Jan Balewski's user avatar
2 votes

The result of qiskit calculating T-depth and its calculation method

Looking at the code that implements the .depth() method for a QuantumCircuit, it seems that when using a ...
diemilio's user avatar
  • 640
2 votes
Accepted

Hamiltonian Simulation: What's the meaning of t in $\exp(iAt)$?

If your eigenvalues of $A$ are $\lambda_n$, then the eigenvalues of $e^{iAt}$ are $e^{i\lambda_n t}$. These values are periodic in $2\pi$, which could lead to some ambiguity in correspondence between ...
DaftWullie's user avatar
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2 votes

qiskit_aer.aererror.AerError: 'unknown instruction: ccry'

This is because the Aer simulator does not directly support certain custom or advanced instructions. Make sure to transpile your circuit before running it. ...
ozark's user avatar
  • 31
2 votes

Error 400 on Variation Quantum Algorithm

This may be due to the changes that IBM made to sessions on 29 April: https://docs.quantum.ibm.com/announcements/product-updates/2024-04-22-session-changes The Open Plan will execute in job mode with ...
Bart's user avatar
  • 121
2 votes
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For CHSH game, why does the mathematica program gives 75% as the best winning rate when sharing 2 EPR pairs?

I think the problem you're having is with your tensor product structure. If you label the qubits 1 to 4, then your A measurements are on qubits 1 and 2, while your B measurements are on qubits 3 and 4....
DaftWullie's user avatar
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2 votes
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General number of classical bits: recycles qubits

You can use the unpacking operator: qc = QuantumCircuit(m, w, *[cl_reg[i] for i in range(M)])
Tristan Nemoz's user avatar
  • 6,712
2 votes
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Can non-linear operations be implemented as a circuit on a quantum computer?

If you mean any kind of circuit, or more general quantum operation, that takes as input some $\rho$, and produces output probabilities equal to $\operatorname{tr}(\rho_A^2)$, or more generally a ...
glS's user avatar
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1 vote

Different notations for measurement gates: what is meant by $0$ after a measurement?

Typically, single-line wires are usually reserved for qubits, whereas double-line wires are used for classical bits. When you perform a projective measurement on a quantum state, the measurement ...
diemilio's user avatar
  • 640
1 vote
Accepted

inverse function in qiskit not generating inverted circuits

qc.inverse() is not an in-place function; instead, it returns a new QuantumCircuit object. Replace your code with: ...
diemilio's user avatar
  • 640
1 vote
Accepted

Reading QuantumClifford.jl MixedDestabilizer state from a .csv file

I figured it out, and I wrote functions for reading/writing Clifford states: Writing: ...
momiamfine's user avatar
1 vote

Can non-linear operations be implemented as a circuit on a quantum computer?

If you have two copies of $|\psi\rangle$, you simply perform the swap test on the "A" components.
DaftWullie's user avatar
  • 59.5k
1 vote

How to implement a quantum multiplier in Qiskit 1.0

Similarly to other backends, Aer only supports a limited amount of basis gates. Thus, you have to first transpile your circuit to work with your desired backend. So, simply uncommenting the ...
Tristan Nemoz's user avatar
  • 6,712
1 vote
Accepted

Obtaining and Applying XX and ZZ Parity in Stim for Controlled Paulis

Stim's supported gates documentation includes the gate MXX and the gate MZZ which are exactly the two-qubit parity measurement ...
Craig Gidney's user avatar
  • 38.8k
1 vote

The result of qiskit calculating T-depth and its calculation method

In the first figure you added barriers which prevents a transpiler from circuit optimization. This means that T-depth can be higher than in case of the circuit without barriers. On first qubit you ...
Martin Vesely's user avatar
1 vote
Accepted

Qiskit error: too many subscripts in einsum when calling DensityMatrix.evolve(Operator)

It seems this is not a Qiskit issue but rather a limitation in the maximum number of indices the numpy.einsum function is capable of handling (max is 26, as ...
diemilio's user avatar
  • 640
1 vote

IBMBackendValueError: number of circuits exceeds the maximum for this backend, 300

Right, I also see no max explicit parameter capping the number of iterations in qml.AdamOptimizer(). You can always solve it 'manually' by adding a counter of ...
Jan Balewski's user avatar

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