Stack Overflow
Stack Overflow

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
6
votes
5 answers

How do qubits work and what are their pros and cons? What impact will they have on programming languages?

What can we do more with qubits than normal bits, and how do they work? I read about them some time ago, and it appears that qubits can store not just 0 or 1, but also 0 and 1 at the same time. I don't really understand how they work. Can someone…
user142019
6
votes
2 answers

Solve ode in python with complex matrix as initial value

I have a von Neumann equation which looks like: dr/dt = - i [H, r], where r and H are square matricies of complex numbers and I need to find r(t) using python script. Is there any standart instruments to integrate such equations? When I was solving…
krems
  • 749
  • 6
  • 14
5
votes
2 answers

How to create unitary gate from np.array in qiskit?

Hi all: Cirq offers a way to create a unitary gate from an array. I tried doing the same in Qiskit but have not been able to quite make it. Here is a sample code with what I could put together so far. Also, is there a way to apply the controlled…
Vox
  • 173
  • 1
  • 8
5
votes
2 answers

Q# compiler errors in Quantum Development Kit on macOS

I have a compilation error of this simple Q# example of newly Microsoft Quantum Development Kit: namespace Quantum.Bell { open Microsoft.Quantum.Primitive; open Microsoft.Quantum.Canon; operation Set (desired: Result, q1: Qubit) : Unit …
loretoparisi
  • 15,724
  • 11
  • 102
  • 146
5
votes
1 answer

How to realize the Grover's Diffusion Operator in Q#?

Like the title says, how to realize the Grover's Diffusion Operator in Q#? I know it's defined as 2 ⟨s|s⟩ - I where |s⟩ is the uniform state for any arbitrary number of qubits. This can further be defined in terms of Z0 (saw it called U0) gate…
Indrajit Banerjee
  • 408
  • 3
  • 12
5
votes
2 answers

Is Microsoft Q# .Net framework compatible?

Q# is an interesting new language from Microsoft dedicted to performing quantum computation. Does it compile to a .net library that can be referenced from c# or any other .net language .Net Framework and/or .Net Core Framework (.Net standard…
jjaskulowski
  • 2,524
  • 3
  • 26
  • 36
5
votes
1 answer

Can the difference between qubit and bit be explained with a simple code example?

The only places I know that you can play with quantum computing are the google quantum playground and the ibm's quantum experience. While the first one uses qscript and the second qasm languages (which are easy to learn) their usage still do not…
npocmaka
  • 55,367
  • 18
  • 148
  • 187
5
votes
3 answers

Why must the value of a qubit in quantum computing remain secret?

I've read time and again, as I dig through all the available literature, that in quantum computing, the smallest unit of value--a qubit--must remain "secret" or unknown until such a time as it is measured. In StackOverflow, I even read that, "in…
ShieldOfSalvation
  • 1,297
  • 16
  • 32
5
votes
5 answers

Anybody interested in possible operation/use of quantum computers?

I went through a period of being interested in how quantum computers work and what they might be good for if they ever become practical. I know they are talked about for code-breaking. I was interested is using them for validating software by…
Mike Dunlavey
  • 40,059
  • 14
  • 91
  • 135
5
votes
1 answer

Quantum Fourier Transform code for 3 qbits

Background I came across a Javascript quantum simulator and was trying to write the code (i.e. the quantum circuit) to implement a 3 qbit Quantum Fourier transform. The closest I could get is shown below: This is based on the chapter on the QFT…
Peter de Rivaz
  • 33,126
  • 4
  • 46
  • 75
4
votes
3 answers

What is a QBit and how soon can I get a quantum computer?

How soon can I get a quantum computer? Is there any way to build a simple one? How many years out are they for early early adopters? I'd like to understand from a high level what a QBit is, how many states it can have, and what types of…
alchemical
  • 13,559
  • 23
  • 83
  • 110
4
votes
2 answers

Getting 'Figure(..x..)' when drawing quantum circuit with qiskit “mpl” output mode

I am just starting with Quantum Computing and I tried the following code. from qiskit import * qr = QuantumRegister(2) cr = ClassicalRegister(2) Qc = QuantumCircuit(qr,cr) print ('This is the initial state') print(Qc.draw(output = 'mpl')) print…
Utsav Niroula
  • 41
  • 1
4
votes
1 answer

The Universtal Gate U(theta, phi, lamda) in Open QASM vs Qiskit

I have noticed that Open QASM and Qiskit define the universal single-qubit gate U(lambda, theta, phi) differently. The difference causes a phase difference in RZ, for example. Has anyone come across this problem? Which should one choose?
Robert Singleton
  • 141
  • 5
4
votes
1 answer

Testing the Q# code on a real quantum computer?

I am using the Microsoft Quantum Development Kit for Python. Can I run the code on a real quantum computer? Thanks for answers.
codingislife
  • 43
  • 3
4
votes
1 answer

Q# Console Template DOTNET not working on MAC

$ dotnet new console -lang Q# --output Bell Error: Invalid parameter(s): -lang Q# 'Q#' is not a valid value for -lang (language). Run dotnet new console --help for usage information. See https://aka.ms/dotnet-install-templates to learn how to…
BPDESILVA
  • 2,040
  • 5
  • 15
  • 35
1
2
3
…
24 25