Questions tagged [open-quantum-systems]
For questions about the effect of a quantum system's environment on the system of interest.
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Generators of positive quantum evolution
It is known that a generator of completely positive evolution, a Lindbladian $\mathcal{L}$, can always be represented in the following form:
\begin{equation*}
\mathcal{L}(\rho) = -i [H,\rho] + \Phi(...
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QuTiP tutorial: How to derive the analytical solution to the expectation value of an operator for a system evolving by Lindbladian
I am following the simple tutorial below:
(https://nbviewer.org/urls/qutip.org/qutip-tutorials/tutorials-v5/time-evolution/003_qubit-dynamics.ipynb)
In this they look at single qubit with Hamiltonian $...
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Do all Hermiticity-preserving maps generate completely positive maps?
I am confused about what kinds of maps are valid infinitesimal generators of completely positive maps. I know that any Markovian completely positive map can be written in the form $e^{t \mathcal{L}}$, ...
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What are kraus operators of a qubit interacting a thermal environment?
Suppose a qubit that interacting a thermal environment. The thermal environment can be a thermal field for example. What is the kraus operators for this case?
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For how many different times do I have to know that $e^{tL}$ is a quantum channel to conclude that $L$ is of Lindblad form?
As first shown by Gorini, Kossakowski, Sudarshan and Lindblad given some linear map $\mathcal L:\mathbb C^{n\times n}\to\mathbb C^{n\times n}$, $e^{t\mathcal L}$ is a quantum channel for all $t\geq 0$ ...
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How to view operator norms on open-system representation of quantum channels
I know how the operator norms $\| X\|_{1}$,$\| X\|_{2}$, and $\| X\|_{\infty}$ are defined for any operator $X\in B(\mathcal{H})$. My question is about how to view$\| T(X)\|_{1}$,$\| T(X)\|_{2}$, and ...
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Feedback control with feedback Hamiltonian vs quantum error correction
I stumbled upon a pretty old paper from 2003 by C. Ahn, H.M. Wiseman and G.J. Milburn. They use quantum control with feedback Hamiltonian to perform error correction. The paper proposes to encode $n-1$...
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What are the singular values of a quantum channel?
I have tried to find the explicit definition of them but was not able to. My guess is that they are eigenvalues of the superoperator $\Phi^{\ast}(\Phi)$, where $\Phi$ is the channel and $\Phi^{\ast}$ ...
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How can we derive the form of POVMs on a subspace from a projective measurement on a larger space?
Suppose we have the Hilbert space $\mathcal{H}_{0}$ describing the states of the system $s$, and the Hilbert space $\mathcal{H}_{e}$ describing the states of the environment. I have seen that [1][2], ...
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What kinds of objects are Liouvillian, Lindbladian, and Davies generator?
I have a rather basic question. I'm starting to read papers such as Chen–Brandao, Chen–Kastoryano–Brandao–Gilyen, and I'm having trouble parsing even what kind of objects a Liouvillian, Lindbladian, ...
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Simulate dual Lindblad master equations in the Heisenberg picture in QuTiP
In QuTiP, it is possible to solve Lindblad master equations describing the time evolution of an open quantum system $\rho$:
$$
\dot{\rho}(t)=-\frac{i}{\hbar}[H(t), \rho(t)]+\sum_n \frac{1}{2}\left[2 ...
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Notation for Lindblad operators
I was reading the paper Quantum computation, quantum state engineering, and quantum phase transitions driven by dissipation
. The claim is that universal quantum computation can be achieved using the ...
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Distribution of density operators under Stochastic Master Equation
Stochastic master equations (SME) are used in studies of open quantum systems. The general form of an SME is:
\begin{align}
\tag{1} d\tilde{\sigma}(t) = - i [H, \tilde{\sigma}(t) ]dt + \frac{1}{2}\...
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how to fix error 'QiskitBackendNotFoundError' [closed]
This is my code:
from qiskit import IBMQ
IBMQ.load_account()
provider = IBMQ.get_provider('ibm-q')
qcomp = provider.get_backend('ibmq_16_melbourne')
...
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Will quantum computers of the future be operational under room temperatures (above 0 Celsius)?
In the future of Quantum Computing, will it be possible to see quantum computers operating under room temperature like the personal classical computers or normal laptops that we have currently?
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