Questions tagged [wigner-function]

A quasiprobability distribution function proposed to account for quantum corrections to classical statistical mechanics with a goal to link the wavefunction that appears in Schrödinger's equation to a probability distribution in phase space.

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Invert colors in qutip plot_wigner function

In QuTiP, it is possible to plot Wigner functions with positive (shown in blue) and negative (shown in red) values. For example, the following code displays the Wigner function of a Schrodinger cat ...
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Are there non-stabilizer multi-qubit states that are easy to simulate?

The Gottesman-Knill theorem states that the following process is efficiently simulatable on a classical computer: start of with a set of qubits in a computational basis apply any amount of $H, S$ and ...
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Evaluation of Wigner function representation of a Bloch Sphere

Consider Wigner function representation of a qubit in the basis labeled by $\sigma_z$ and $\sigma_x$ eigenvalues. A general single qubit mixed state has the Bloch representation,$\rho = 1/2 (I + r.\...
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Finding Wigner function of four maximal entangled Bell state

How can we find a Wigner function for the four maximally entangled Bell states $(|00\rangle \pm |11\rangle)/\sqrt{2}$, $(|01\rangle \pm |10\rangle)/\sqrt{2}$? I have used the basis where labels for ...
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Properties of frames in quasiprobability representation

Let $\mathbb{C}^{d}$ be a complex Euclidean space. Let $\mathsf{H}(\mathbb{C}^{d})$ be the set of all Hermitian operators, mapping vectors from $\mathbb{C}^{d}$ to $\mathbb{C}^{d}$. I had some ...
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What is the relation between density matrices and phase-space probability distributions?

According to its tag description, a density matrix is the quantum-mechanical analogue to a phase-space probability measure (probability distribution of position and momentum) in classical statistical ...
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Relation between Wigner quasi-probability distribution and statistical second-moment

Is there any relation between the Wigner quasi-probability distribution function $W$ and the statistical second-moment (also known as covariance matrix) of a density matrix of a continuous variable ...
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Does a Wigner function uniquely determine a quantum state?

We know that the Wigner function of a Gaussian quantum state is (up to a constant) a Gaussian distribution. The first moment and the covariance of this distribution uniquely specify a quantum state. ...
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What does negative probability represent?

"Negative energies and probabilities should not be considered as nonsense. They are well-defined concepts mathematically, like a negative of money." -Paul Dirac The abstract from Photon-phonon-photon ...
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