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Questions tagged [quantum-computing]

Quantum Computation deals with considering computation as fundamentally physical, as well as replacing the classical binary digit (bit) with the quantum binary digit (qubit). While the classical bit is either 0 or 1, the qubit can be in a superposition of these states. Computation systems that use quantum phenomena, such as superposition and entanglement, can solve certain complex problems very quickly.

Related Links

Quantum Computing on Wikipedia

(Textbook) Quantum Computation and Quantum Information: The de-facto standard textbook for learning about quantum computing.

(Video Series) Quantum computing for the determined: Khan-academy-style videos explaining quantum computation, by Michael Nielson (co-author of Quantum Computation and Quantum Information).

Quantum Computing Q&A site on the Stack Exchange network.

369 questions
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How to make a gate which generates |0> or |1> based on a parameter?

I would like to make a single-qubit gate which gives |0> or |1> with reference to a parameter. For example, I set a parameter theta in range of 0 to 2π. When theta is in range of 0 to π, the gate returns |0> and when theta is in range of π to 2π,…
Ashy
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Getting error "Released qubits are not in zero state" in Q# Quantum Dev kit

When running the following simple quantum program to apply Hadamard gate to a single qubit: operation ApplyHadamard():() { body { using (qubits = Qubit[1]) { H(qubits[0]); } } } I get the following…
Hugo Nava Kopp
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Quantum V gate 1/sqrt(5) ( I + 2iZ)

By definition, the gate 1/sqrt(5) (I + 2iZ) should act on a qubit a|0> + b|1> to transform it into 1/sqrt(5) ((1+2i)a|0> + (1-2i)b|1>) but transformations of each RUS step does the following- The ancillas are in |+> state at first Starting form: …
Indrajit Banerjee
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'TeleportClassicalMessage' does not exist in the current context

I am trying to run the Q# Teleportation sample. I cloned from the official Microsoft GitHub Repository, restored all dependencies, I have the Q# Development SDK installed also. The problem is when i run it the first time it worked now i tried…
Frank Odoom
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VisibleDeprecationWarning - where is this coming from?

I'm writing some code to simulate a quantum computer in python. I just added a section which starts integrating greater-than-one-qubit functionality, and then this weird error came up. It doesn't say anything about which line caused it, so I don't…
Auden Young
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How to visually represent multi-qubit system in Python?

I am trying to visually show a comparison between a 3-qubit system before and after a certain algorithim/gate has been performed on it. For examle 3 qubit system before and after Hadamard gate psi = 1|000> + 1|001> Hadamard 3-Qubit matrix H = …
Catherine
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Quantum computing simulation in QASM

I am using IBM's Quantum Experience and I have a small problem. Dragging and dropping the gates takes a while, and they don't have a Toffoli gate. So I have to redrag in the gates that construct the Toffoli gate and it takes a while. The composer…
Auden Young
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Error trying to install QCL (Quantum Computation Language) on Mac 10.11

I am trying to install QCL-0.6.4 from this source, but I keep getting errors, when I try it with the make command in the terminal. I came along this thread about installing QCL on OSX, but when trying to adjust the Makefile I always come across this…
Julian
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How Will Register Transfer work in a Quantum computer ?

If i am not wrong a qbit can have any value from 0 to 1 at any given time , But if you are moving some data from a register to another in a quantum computer how will we know what state will be transferred , to the register ?
Namit Sinha
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How can I run QCL (quantum programming language) on Windows?

I'm sure someone must have done this before. I've tried compiling QCL for Cygwin but it just doesn't work. If someone has already managed to compile it for Cygwin can you please post a copy? Or alternatively suggest an easier way to run it in…
Gary Garygary
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How to define the number of times to run a circuit in Qristal SDK?

I've been starting to create a quantum application using the Qristal SDK. I've gotten it running in a Docker image and successfully printed results from using a qpp back end with a kind of hello world count exercise (trying to see that it does in…
Nina Computer
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'RecursionError: maximum recursion depth exceeded' when training with QuantumKernelTrainer inside a QisKit IBM Runtime Session

I am encountering a RecursionError when using the QuantumKernelTrainer class during the fitting process of a TrainableFidelityQuantumKernel object from the qiskit_machine_learning package within a Qiskit IBM Runtime session. To train the classifier…
Rober
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Errors when using MCMT to create a multi control cz gate and trying to measure

Multi control cz gate: The error is saying that: [Experiment 0] Circuit mcmt contains invalid instructions {"gates": {ccz}} for "statevector" method. , ERROR: Circuit mcmt contains invalid instructions {"gates": {ccz}} for "statevector" method.'
Sakibul Islam Rayhan
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QKD BB84 protocol: Is confirmation of the qubit possible? Or does the two generals problem apply?

In the Quantum Key Distribution protocol BB84, Alice sends x qubits to Bob. There is no acknowledgement of receipt. This cannot be done over the quantum channel. If I need an acknowledgement, it must be sent via a classical channel. But that means…
Duckling
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Need an explanation for a quantum model

When I am reading chapter 10 of Dasgupta I faced a paragraph that I can't understand: An electron can be in a ground state or in an excited state. In the Dirac notation used in quantum physics, these are denoted 0 and 1. But the superposition…
amir amir
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