## Complex samples are inconsistent

When we draw samples with complex `dtype`

, we multiply their magnitude with `sqrt(0.5)`

.
This is done because then a sample from a variance of 1 also has standard deviation of 1 on average.
However, this is inconsistent with its Hamiltonian.
If we instead regard a complex number as a pair of real numbers, then in order to reproduce the sample variance, we would need the vector (real, imag) to have covariance

```
/ 0.5 0 \
| |
\ 0 0.5 /
```

However this covariance would lead to the Hamiltonian `(real**2 + imag**2)*2`

which is double of what we would get when using the complex likelihood with covariance 1.