Questions tagged [depolarizing-channel]
A model for noise in quantum systems such as a decohering qubit that has particularly nice symmetry properties. The depolarizing channel is a “worst-case scenario” channel. It assumes that we just completely lose the input qubit with some probability, i.e., it replaces the lost qubit with the maximally mixed state.
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Why is the Choi matrix different from the analytic form for a depolarizing channel?
I'm currently trying to implement the depolarizing channel on qiskit. But, as I see in my calculation it doesn't match with the qiskit aer_noise.
So, for the Depolarizing Channel we got :
$$
\mathcal{...
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How can the depolarizing channel be a quantum operation?
In Quantum Computing: From Linear Algebra to Physical Realizations it states that
A quantum operation maps a density matrix to another density matrix linearly
But let $\rho\in M_2$ be a density ...
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Depolarizing channel on GHZ-state
Consider a GHZ-state $|\psi\rangle =\frac{1}{\sqrt{2}}(|0\rangle^{n}+|1\rangle^n)$, and consider a depolarizing channel that maps a density matrix
$$\rho\to(1-\lambda)\rho + \frac{\lambda}{2^d}I.$$
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Trouble in Depolarizing Error Simulation with Qiskit
I'm currently attempting to simulate depolarizing errors using Qiskit, but I'm encountering an issue where it appears that no errors are being introduced into my simulation. After running the ...
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Decoding the Steane Code
The $[[5,1,3]]$ code is a perfect code basically meaning that the weight-0 and weight-1 error spaces completely fill out the $32$-dimensional Hilbert space.
On the other hand, the $[[7,1,3]]$ Steane ...
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Is the "unitary twirling operation" physically realizable?
In this neat answer by Markus Heinrich, it is shown that twirling an arbitrary quantum channel $\Lambda$ over the unitary group $U(d)$ yields a depolarizing channel $\tilde{\Lambda}$ given by
$$
\...
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Partial decoherence of a general one-photon state
Let $\rho_1$ be the pure one-photon state described by the ket
$$|\psi_1\rangle = \int dk\ A(k)a^\dagger(k)|0\rangle$$
for a complex amplitude function $A(x)$ and an empty ket $|0\rangle$. This state ...
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Why does depolarising channel shrinks Bloch vectors?
Let's start with
$Tr_{\Omega}[U|0,\Omega_{0}\rangle\langle0,\Omega_{0}|U^{\dagger}] = \sum_{\alpha}E_{\alpha}|0\rangle\langle0|E_{\alpha}^{\dagger}$
where $U$ be a unitary operator. The trace operator ...
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Physical description of trace of ancilla state yields a depolarising channel
Let's start with
$Tr_{\Omega}[|0,\Omega_{0}\rangle\langle0,\Omega_{0}|U^{\dagger}] = \sum_{\alpha}E_{\alpha}|0\rangle\langle0|E_{\alpha}^{\dagger}$
where $U$ be a unitary operator. The trace operator ...
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How does depolarization error accumulate?
Here's my code to define the depolarization error using Qiskit, which included both one and two-qubit errors:
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Qiskit Aer Noise Module
I am trying to use the following single qubit depolarizing channel (on a GHZ state for example) but the simulation histogram counts are not affected
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How to see the effects of the depolarizing channel in qiskit?
I am playing around with adding noise to quantum circuit simulation using qiskit_aer.noise.NoiseModel(). My code creates a quantum circuit and simulates it with ...
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What does adding depolarizing error on a Hadamard gate mean mathematically?
I have a quantum circuit as the following picture. Now I add the depolarizing error on the Hadamard gate using the following code in Qiskit.
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Diamond norm distances between some channel and the identity
I'm currently working with the continuity result by Kretschmann-Schlingemann-Werner (arXiv version) for Stinespring isometries (more precisely, the following corollary to their result, cf. Appendix C ...
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Recover the noisy POVMs of Bell basis measurement
Considering Bell basis measurement, we have that the ideal POVMs are four Bell states, which can be obtained by reversing the following quantum circuits. Now, we add depolarizing errors to CX gate and ...
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