Image credit: https://commons.m.wikimedia.org/wiki/File:Bloch_sphere.svg#mw-jump-to-license

I was searching for IBM Q Experience experiments through GoodSearch and on YouTube and found this:

It’s not really an experiment, per se, yet I hadn’t tried it. Basically, this puts 5 quantum bits (qubits) into superposition states and then measures each qubit individually.

Since the drag-and-drop interface does not work on my smartphone, I once again wrote the code using QASM (Quantum Assembly Language):

Line 3 and 4 initialize the qubits to a ground state of zero; this is always the first step. Lines 6 through 10 apply Hadamard gates to each qubit; this is what puts them into superposition states. Finally, lines 12 through 16 measure the qubits.

The resultant histogram shows a relatively equal probability of each possible outcome, from all zero states to all one states.

This got me thinking about measuring just one qubit. Theoretically, there should be an equal probability of a one or a zero. So, I stripped out the unneeded code:

As you can see, it’s the same code as before, but only including the lines referencing qubit q[0].

After running the code, I can look at it graphically.

Quantum systems are imperfect, so the results are imperfect. After setting the single qubit to a ground state of zero and then putting it into a superpositiom state, it is still probably zero, but also possibly one.

I’m still searching for more challenging projects, but, in the meantime, playing with electrons is too fun to pass up.