# Questions tagged [quantum-circuit]

a model in which a computation is a sequence of quantum gates, which are reversible transformations on an n-qubit register (the quantum-mechanical analog of an n-bit register)

495 questions
Filter by
Sorted by
Tagged with
83 views

### Quantum circuit implementation of shift operator in quantum walk

I'm considering discrete-time quantum walk on $2\times2$ grid with periodic quantum walk. In particular focus on shift operator which has the form : S|i,j\rangle \otimes |x,y\...
342 views

### AerError: 'unknown instruction: c-unitary' while using control unitary operator

I'm using the following code : ...
1 vote
60 views

### What is the unitary matrix for this two qubit circuit with $H$ and $I$?

Above is a circuit I am provided. I am asked to write down the matrix representation of a $4 \times 4$ matrix representation of a unitary matrix for this circuit. Using small endian notation (left to ...
• 520
175 views

• 393
147 views

### How do I prove these gate identities?

How do I approach on solving the below two problems?
120 views

• 392
259 views

### What is the "additive error" of Swap Test?

I'm learning the Swap Test, a quantum circuit to calculate the inner product of two quantum states $|\langle \phi|\psi\rangle|^2$: For the error analysis of this quantum circuit, according to Swap ...
• 355
212 views

### Trying to understand a quantum adder

I've implemented a quantum adder and, when I build the results table, I'm having some trouble to understand what's going on. First, I'm using the adder quantum circuit proposed in this paper, which ...
1 vote
67 views

### how to convert a qiskit circuit to pauli strings

I have a qiskit quantum circuit that i want to convert to pauli strings (coefficients,observables) so that i can use it to build a hamiltonian. I did not see any methods in qiskit quantumcircuit ...
• 11
330 views

### How to get QASM code from an Amazon Braket circuit in Python?

As an example, consider the following Circuit defined by using the Python amazon-braket-sdk: ...
• 1,452
1 vote