Quantum Computing Stack Exchange
Quantum Computing Stack Exchange

Questions tagged [qubit-mapping]

For questions on the process of mapping virtual qubits to physical ones when transpiling a quantum circuit. For questions that are about mapping some quantity to a qubit representation, use the encoding tag.

21 questions
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Copying |0⟩, |1⟩ Qubits will break the no-cloning theorem?

I am trying to create a bit string of |0⟩'s and |1⟩'s in order to create an array. Would this still break the no-cloning theorem since we do know their state: they are |0⟩'s and |1⟩'s. If possible, what I am trying to do is that I have the following…
Evan Camilleri
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Is it possible to build a "Quantum Karnaugh Map"?

Is it possible to build something similar to the Karnaugh Map but instead of classical bits input and output with qubits input and output?
Miss Mulan
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Coupling maps in quantum computation

Perhaps a bit naive question from my side, but I could not find any satisfactory answer elsewhere: What exactly are the coupling maps in quantum computation and, more particularly, how do those maps translate to CouplingMap objects in…
Akhaim
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Mapping Layout for Qubits in Optimization Level = 0

I am currently running a job on a quantum computer. During the transpilation process, I set optimization_level=0 using the command: "tqc = transpile(qc, backend=backend, optimization_level=0)". However, when I try to inspect the qubit mapping via…
Lham
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Fermionic to Qubit Mappers for Particle Conservation

I'm trying to obtain a Hamiltonian to implement a simple QPE algorithm. I got the FermionicOP from second quantization, and now I need to convert it to a SparsePauliOP using a mapper. I've managed to do this with the JW, Parity, and BK mappings.…
Luis Duarte
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Using qubit mapping in the Hubbard model to describe Cooper pair entanglement and teleportation

I'm exploring how the Hubbard model might be used to represent superconductivity, particularly regarding the entanglement properties of Cooper pairs. When a Cooper pair forms between two fermions on the same site, they are expected to exhibit some…
Lawerence
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Why does Parity mapping allow 2 qubit reduction?

when mapping from fermionic to qubit hamiltonian, using Parity mapper allow us to reduce 2 qubit in the final hamiltonian. I would like to understand which kind of symmetries are being used and how it is done. Thank you in advance!
bjail66
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How do we know CNOT gate is working properly?

To my current, and very limited knowledge. The CNOT gate is a function that should map 4 possible combinations of input, into 4 possible states It happens, we theoretically expect 4 states in output with 25% chance. In reality we measure roughly 2…
CoffeDeveloper
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What‘s the largest int a modern quantum computer can handle?

I‘m just starting out with this topic and it’s already a bit confusing: I was just wondering, if I could take a really, really big number, let’s say a 256-bit number and add another number to it on a quantum computer (or simulation). There’s no…
Ted Met
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Understanding Phase Maps and Dephasing in a Periodically Driven Qubit System

I am working on a periodically driven qubit system and trying to understand the concepts of phase maps and dephasing. Here is the setup: The initial qubit state is given by: $\cos(\theta/2)|0\rangle+\sin(\theta/2)e^{i\varphi}|1\rangle$ The…
Rebecca
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Qiskit result interperation - about qubits measurments and visualization

I am new to quantum computing and was playing with circuits. I came across measurements method in qiskit, and from what I understand is that when measured, each qubit is mapped to different classical bit. I know that might be weird, and I am very…
user26416177
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How to easily get the number of qubits required when using QAOA from qiskit_algrithms?

I would like to know if there is a easy way or native solution to retrieve the number of qubits that is required when using QAOA from qiskit_algorithms package to solve an optimization problem. I understand that QuantumCircuit.num_qubits can do the…
Chuck
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What do arbitrary encoding circuits provide?

I'm about to implement my first VQC for image classification and I'm trying to figure out which data encoding method could fit better the problem. From what I've understood, there are three main approaches to encode classical data into quantum…
Paul
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Using machine learning to determine a good initial mapping for a quantum circuit

I am trying to use a machine learning model to find a good initial mapping for a quantum circuit. I am trying to minimise the number of swap operations i.e. the number of CNOT gates. This is my methodology - Generate a random quantum circuit with…
Anonymous
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Specifying Ancilla qubits for initial_layout parameter in qiskit.transpile

So I have an array which specifies the initial layout of a 4 qubit quantum circuit and I want to map the qubits to a 5 qubit quantum computer. As only 4 out of the 5 qubits will be used, Qiskit assigns one of the vacant qubits on the quantum…
Anonymous
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