Recently I wanted to use the Aer device but the solution of @roy-elkabetz didn't work for me. Maybe the library has changed the name of the package or the way you should import it.

After a little bit of search I found the working solution:

First, Install the "pennylane_qiskit" package by running:

!pip install pennylane_qiskit 

Then, import the AerDevice and use it to create your device:

from pennylane_qiskit import AerDevice
dev = AerDevice(wires=4)

The link to the original explanation: Link