Questions tagged [master-equation]
The master-equation tag has no usage guidance.
16
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Is purity convex in time?
Is the purity $\mathrm{Tr}[\rho(t)^2]$ of a quantum state $\rho(t)$ that evolves according to a time-independent Lindbladian $\partial_t \rho = \mathcal{L}[\rho]$ convex in time $t$?
I suspect the the ...
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0
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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 $...
5
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1
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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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Density matrix and State vector give different result in mesolve in QuTiP
qutip mesolve gives me different population evolve depending on that initial state is state vector or density matrix. And, in some situation, it gives me negative population. It doesn't make sense...
...
- 21
2
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1
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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 ...
- 199
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Can superoperators work in Monte Carlo solver in QuTip?
The Monte Carlo solver works with kets instead of density matrices. And it doesn't allow a superoperator (which acts on density matrices or superkets) as a collapse operator. Since my master equation ...
- 183
2
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1
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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 ...
- 2,813
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0
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64
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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}\...
- 2,813
2
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1
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Nielsen and Chuang: Solving equation of motion for amplitude damping
I would like to know how to obtain a solution to the equation of motion given in Section 8.4.1 Master equations of Nielsen and Chuang, 10th edition.
The equation of motion that allows getting the ...
- 2,813
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Qutip: Mesolve gives different and weird results with different fock state numbers
I have been trying to simulate the average number of particles at 3 sites of coupled harmonic oscillators.
I have used the code from the below tutorial:
https://notebook.community/ajgpitch/qutip-...
- 11
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QuTiP VS RK45: Which one gives the correct results for time-dependent systems?
I am writing a code for a quantum thermal machine which includes both coherent and dissipative time evolutions in its different stages of operation. However, evolving the system with "mesolve&...
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Show that if the Lindblad satisfy $\sum_\mu L_\mu L_\mu^\dagger=\sum_\mu L_\mu^\dagger L_\mu$ then $\rho\propto I$ is a fixed point of an evolution
How can we show that the Lindblad condition:
$$\sum_{\mu}L_{\mu} L_{\mu}^{\dagger} = \sum_{\mu} L_{\mu}^{\dagger}L_{\mu},\tag{1}$$
implies that $\rho \propto I$ is the fixed point of the evolution ...
2
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1
answer
164
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How to solve non-"cross-damping off" Linblad equation in QuTiP?
As I understand from the official QuTiP guidlines, it is only capable of solving "cross-damping off" Master Equation in form:
$\dot{\rho(t)} = -\dfrac{i}{\hbar}[H(t),\rho(t)] + \sum\limits_n\...
- 21
5
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What does "generator" mean in the master equation?
I seem to read a lot of times that some materials called this $\mathcal{L}$ in the equation(Lindblad master equation) below as the generator:
$$
\mathcal{L} \rho=-i[H, \rho]+\sum_{\alpha}\left(V_{\...
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What is "Lindblad Superoperator" in Stochastic Master Equation
I was reading a paper titled "Using a Recurrent Neural Network to Reconstruct Quantum Dynamics of a Superconducting Qubit from Physical Observations" and was confused about a stochastic master ...
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