I am trying to simulate an experiment on IBM's melbourne quantum computer and here are the results

1. Qasm simulator :

2. ibmq_16_melbourne:

3. error

why is there such high probability of unwanted states i.e 01 and 10. Also when the circuit is transpiled on the melbourne computer the circuit operates between $$q[4]$$ and $$q[10]$$, is these usual.

What I've found in my experiments is that what usually ruins an experiment is the error associated with the CNOT operation, you can keep track of their count by using something along these lines qc.count_ops().get('cx'). Another thing that may help is setting the layout method to "noise adaptive", by including layout_method='noise_adaptive' into the transpiler parameters. You should check the transpiler documentation and play around with the different parameters in order to best optimize your gate count. Ultimately the transpiler can only do so much and your circuit might just not be able to run on a real device.
• In the error map, the average error for C-NOT is $37\%$, isn't that a bit high, because that could lead extremely inaccurate results – Upstart Jul 29 '20 at 19:45