Wigner Distribution Function for Harmonic Oscillator

​
quantum number n
20
This Demonstration shows the Wigner quasiprobability distribution for 101 energy states of the quantum harmonic oscillator. Units are chosen so that the energy operator is simplified to
H=
1
2

2
p
+
2
q

.
Quantized energy values are
E
n
=n+
1
2
. Polar coordinates are used in the phase space. The Wigner radial quasiprobability distribution is defined by
P(r,p)=
1
πℏ
∞
∫
0
ψ(r+s)ψ(r-s)
2ps/ℏ
e
2
s
ds
,
noting that
ψ
is real. The distribution is normalized and plotted as a function of
r
. For each
n
, the variable
r
and the distribution are rescaled so that the classical turning points (normally at
r=
2n+1
) are all at
r=1
.

Details

The vertical red line at
r=1
indicates the classical turning point. Beyond this point is the classically forbidden region. The area under the plot to the right of this line is the quasiprobability of the nonclassical quantum tunneling behavior. For
n=0,…,100
, this area is between 0.37 and 0.33. Yet, owing to the nonpositivity of the Wigner distribution, the meaning of these numbers is open to interpretation.

References

[1] Wikipedia. "Wigner Quasiprobability Distribution." (Jan 22, 2015) en.wikipedia.org/wiki/Wigner_quasiprobability_distribution.
[2] Wikipedia. "Quantum Harmonic Oscillator." (Jan 22, 2015) en.wikipedia.org/wiki/Quantum_harmonic_oscillator.

External Links

Wigner Function of Harmonic Oscillator

Permanent Citation

Arkadiusz Jadczyk
​
​"Wigner Distribution Function for Harmonic Oscillator"​
​http://demonstrations.wolfram.com/WignerDistributionFunctionForHarmonicOscillator/​
​Wolfram Demonstrations Project​
​Published: January 26, 2015