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Questions tagged [pauli-gates]

For questions about Pauli matrices in general or Pauli gates in particular, as relevant to quantum computing and/or quantum information theory. The Pauli matrices are a set of three 2 × 2 complex matrices which are Hermitian and unitary. The three Pauli gates are: Pauli-X gate, Pauli-Y gate & Pauli-Z gate. X = {{0,1},{1,0}}; Y = {{0,-i},{i,0}}; Z = {{1,0},{0,-1}}.

0 votes
1 answer
49 views

In Fowler's paper, "Surface codes: Towards practical large-scale quantum computation" (link), a rudimentary probabilistic model for logical errors is described. My only issue with this is ...
Arya K's user avatar
  • 41
1 vote
2 answers
253 views

In this article: http://home.lu.lv/~sd20008/papers/essays/Clifford%20group%20[paper].pdf , the author calculates the order of the Clifford group and there is one step I'm not convinced. Consider $n$ ...
cos's user avatar
  • 79
2 votes
1 answer
95 views

I recently noticed that some quantum computers supply native gate $$iSWAP_{\theta} = e^{-i \theta (XX + YY)}.$$ I wonder, how do I build a circuit for $$e^{-i \theta Z\otimes(XX + YY)}$$ Is this one ...
Daniele Cuomo's user avatar
2 votes
0 answers
107 views

Let $\mathcal{P}$ denote all Pauli operators (Heisenberg-Weyl operators in general). I want to see that $\frac{1}{d^4} \sum_{A_i, B_i \in \mathcal{P}} tr(A_1 U^\dagger B_1 U A_2 U^\dagger B_2 U \...
user1577744's user avatar
1 vote
1 answer
162 views

Can you explain what is this circuit representing? it is supposed to perform measurement using Pauli operator P non destructively? How is that happening in this circuit?
Arjun Sigdel's user avatar
0 votes
2 answers
105 views

Is there a rotation operator that doesn't change the outcome probability when measuring either on basis X or Z in the scenario where I only change the sign of the angle? I was thinking of $R_y(\pm\...
Daniele Cuomo's user avatar
0 votes
1 answer
89 views

This is a follow up of this question I am getting a bit confused about how to properly build a circuit implementing Pauli exponentiation. I usually start from the standard decomposition of $e^{-i \...
Daniele Cuomo's user avatar
1 vote
2 answers
128 views

According to this paper, for a given Hamiltonian $H$ we can build (efficiently) a circuit that implements $e^{-i \epsilon Y\otimes H}$. I know how to build the circuit in case $H$ is just a single ...
Daniele Cuomo's user avatar
3 votes
2 answers
489 views

I am confused about the Pauli matrices. I am trying to decipher a statement like this: "[...]these three operators form a complete basis for the set of all unitary transformations on a single ...
Matyas's user avatar
  • 167
6 votes
1 answer
369 views

Define $\mathcal{P}_n$ to be the set of all $n$-qubit Pauli strings with phase $+1$. Then any Hermitian operator $H$ can be decomposed into linear combination of these Pauli strings. That is, $$ H=d^{-...
cos's user avatar
  • 79
1 vote
1 answer
180 views

I am learning how to use Qiskit's controlled Pauli gates. For example, I can create a simple three-qubit circuit containing controlled Pauli-XX and -ZZ gates using the code: ...
Medulla Oblongata's user avatar
2 votes
2 answers
429 views

Given the Hadamard gate $$H = \frac{1}{\sqrt{2}}\begin{pmatrix} 1 & 1 \\ 1 & -1\end{pmatrix}$$ what are the possible values of $\sqrt H$? And what is the geometrical interpretation of $\sqrt H$...
Matteo Vitturi's user avatar
2 votes
2 answers
197 views

Suppose I run a Clifford circuit with noise and send the syndrome data to a decoder. Assume that the decoder's raw output tells me where in the circuit a particular Pauli error occurred. In this ...
juno's user avatar
  • 23
3 votes
2 answers
339 views

Suppose I have a state stabilized by $S = \{S_1, S_2, ... S_n\}$. I want to find another state such that it is the $+1$ eigenstate of all $S_i$ where $i \neq 1$ and the $-1$ eigenstate of $S_1$. I ...
hugo's user avatar
  • 33
3 votes
1 answer
258 views

Consider a system of $ n $ qudits of size $ q $. Suppose that $ | \psi \rangle $ is an absolutely maximally entangled state. In other words, $ | \psi \rangle $ is a state such that the reduction to ...
Ian Gershon Teixeira's user avatar

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