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Is there a tool that can give you the unitary representing a quantum circuit from just a string?
Say I have a string representing the operations of a quantum circuit.
I want to have the unitary operator representing it.
Is there a tool for doing so in Python or else?
cnada
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6
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2 answers
How do we code the matrix for a controlled operation knowing the control qubit, the target qubit and the $2\times 2$ unitary?
Having n qubits, I want to have the unitary described a controlled operation.
Say for example you get as input a unitary, an index for a controlled qubit and another for a target.
How would you code this unitary operation?
cnada
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6
votes
2 answers
Incorrectly Calculating Probability Amplitudes for 3-qbit Circuit
I’m trying to calculate the probability amplitudes for this circuit:
My Octave code is:
sys = kron([1; 0], [1;0], [1;0])
h = 1/sqrt(2) * [1 1; 1 -1];
c = [1 0 0 0; 0 1 0 0; 0 0 0 1; 0 0 1 0];
op1 = kron(h, eye(2), eye(2));
op2 = kron(c,…
Sam Kennedy
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6
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2 answers
What are some good quantum computing simulator and visualiser?
I am looking for some good software to simulate quantum computing, visually if possible.
I know about quirk (http://algassert.com/quirk)
and IBM Q Experience (https://quantumexperience.ng.bluemix.net)
I just saw this question ( Does conditional gate…
Adrien Nivaggioli
- 163
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6
votes
1 answer
Computing of the action of the amplification operator $\mathbf Q$ over $|\Psi_i\rangle$ in the quantum amplitude amplification algorithm
$\newcommand{\Q}{\mathbf{Q}}\newcommand{\S}{\mathbf{S}}\newcommand{\A}{{\mathcal A}}\newcommand{\H}{\mathcal H}$In the quantum amplitude amplification algorithm, as explained in Brassard et al. 2000 (quant-ph/0005055), the unitary performing the…
glS
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6
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2 answers
Anyon alternatives in topological quantum computing
A topological quantum computer is a theoretical quantum computer that employs two-dimensional quasiparticles called anyons. -Wikipedia
Are there other instances of topological quantum computing models that do not use anyons?
Are there alternative…
user820789
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6
votes
1 answer
Quantum error correction: necessary and sufficient condition
For quantum error correction, the necessary and sufficient condition is given in standard texts as:
$\langle \phi| E^{\dagger}_{a} E_{b} |\psi \rangle = C_{ab} \langle \phi|\psi \rangle $
$|\psi\rangle$ and $|\phi\rangle$ are codewords. $E_{a}$ and…
BlackHat18
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6
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1 answer
What kind of mathematics is common in quantum computing?
From what I have seen so far, there is a lot of linear algebra. Curious what other kinds of maths are used in QC & the specific fields in which they are most predominately invoked.
user820789
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6
votes
1 answer
How to get smaller stabilizer codes with Gottesman's construction?
I'm following the construction from Section 3.5 of Daniel Gottesman's thesis (third paragraph), which is supposed to allow us to construct an $\left[ \hspace{-1pt} \left[ n-1, \, k + 1, \, d - 1 \right] \hspace{-1pt} \right]$ stabilizer code $C'$…
Ben Criger
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6
votes
3 answers
Can a CPTP map increase the purity of a state?
I am wondering if there exist CPTP maps $T$ such that the purity of a quantum state $\rho$ can increase, i.e.
$$ \text{tr} ( T ( \rho )^2 ) \geq \text{tr} ( \rho ^2). $$
If so, what are the conditions on $T$ and/or $\rho$ for this to be possible?
Rell
- 61
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6
votes
0 answers
Resources on the energy consumption of IBM quantum computers?
I am seeking information regarding the energy consumption of IBM Quantum Computers, specifically inquiring about the energy requirements associated with individual gate operations.
Could you also provide any available resources or documentation…
goga suknidze
- 61
- 1
6
votes
1 answer
Is the Steane code the only $ [\![7,1,3]\!] $ CSS code?
Is the Steane code the only $ [\![7,1,3]\!] $ CSS code?
This paper claims there are 10 non-equivalent $ [\![7,1,3]\!] $ stabilizer codes. How many of these are CSS codes? Is it just the Steane code?
Ian Gershon Teixeira
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6
votes
1 answer
Is it possible to derive a Schmidt decomposition for a mixed state?
It is relatively simple to derive the Schmidt decomposition of a pure state $|{\psi}\rangle \in H_A \otimes H_B$ with the SVD decomposition theorem. There are plenty of examples (lecture notes, books, videos, etc.) on the subject.
The question I…
JMark
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6
votes
1 answer
Is QFT qubit recycling compatible with Zeckendorf's Fibonacci representation of integers?
Background
Phase estimation circuits prepare $n$ qubits $Q_0, \dots, Q_{n-1}$ in the $|+\rangle$ state, then apply $U^{2^q}$ controlled by $Q_q$ for each $q$, then apply a quantum Fourier transform, then measure $Q_0, \dots, Q_{n-1}$.
"Qubit…
Craig Gidney
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6
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2 answers
Is there a no-go theorem for or an upper bound on code threshold?
My understanding of the code threshold for an $ [[n,1,3]] $ code is something roughly like the setup given in
How to compute the error threshold for the $9$-qubit Shor code?
where the error channel is a depolarizing channel in which no error occurs…
Ian Gershon Teixeira
- 3,722
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