qiskit code for detecting counterfeit quantum coins

I came across this paper describing a quantum algorithm that's a quartic improvement over classical implementations: https://ui.adsabs.harvard.edu/abs/2010arXiv1009.0416I/abstract I also found some code from the QAsm world that claimed to implement a quantum counterfeit coin detector. I translated it into QisKit code: from qiskit import QuantumCircuit, QuantumRegister, ClassicalRegister from qiskit_ibm_runtime import EstimatorV2 as Estimator nbits = 12 # Create a new circuit with 12 qubits and one classical bit qubits = QuantumRegister(nbits) clbits = ClassicalRegister(nbits) qc = QuantumCircuit(qubits,clbits) # Add a Hadamard gate to qubits 0-10 for i in range(nbits-1): qc.h(i) # Perform a controlled-X gate on qubits 0-10, controlled by qubit 11 for i in range(nbits-1): qc.cx(i, nbits-1) qc.measure(nbits-1, nbits-1) with qc.if_test((clbits, 0)): qc.x(nbits-1) with qc.if_test((clbits, 0)): qc.h(nbits-1) for i in range(nbits-1): with qc.if_test((clbits, 1<<(nbits-1))): qc.h(i) qc.barrier(qubits) # qubits[6] is the counterfeit coin with qc.if_test((clbits, 0)): qc.cx(6,nbits-1); qc.barrier(qubits) for i in range(nbits-1): with qc.if_test((clbits, 0)): qc.h(i) for i in range(nbits-1): qc.measure(i, i) But I'm not satisfied that this either implements the optimal algorithm. Has anybody worked on this problem and wants to share any insights as to how to implement the appropriate quantum circuits? submitted by /u/MichaelTiemann [link] [comments]