A set of Python scripts that uses Qiskit to run two or three qubit quantum circuits and display the results as bar graphs on a Raspberry PI SenseHat 8x8 LED display.

• June 2019
  • V0.6 Offline mode. Qrasp checks for internet connection and defaults to Aer simulator if none is found.
• May 2019
  • V0.5 Best backends, and display ibmqx version in selector.
• April 2019
  • V0.4 Backends and display upgrades.
    • Added more IBM Q backends. You can now push the joystick to cycle through:
      • qasm_simulator
      • ibmqx2
      • ibmqx4
    • Color gradients between the red and blue LEDs to indicate results with finer granularity than 1/8 of the bar.
• March 2019
  • V0.3 tested with qiskit-terra 0.7. The v0.6/v0.7 mismatch workarounds in qc_sensehat_func.py removed.
  • V0.2 with updates to run Qrasp against actual IBM Q hardware.
• January 2019
  • V0.1. Qiskit v0.61 and AER simulator.

These scripts were developed and tested with the following hard- and software:

• Hardware
  • Raspberry PI 2B (a21041)
  • Raspberry Pi Sense HAT (v1.0)
• Software
  • Raspbian GNU/Linux 9 (stretch)
  • sense-hat 2.2.0
  • qiskit v0.8 / Qiskit Terra v0.71

This version lets you run four different quantum scripts that demo superposition and entanglement with two and three qubits.

You use the joystick to select the script to run:

• Up: Two qubit Bell state (entanglement)
• Down: Three qubit GHZ state (entanglement)
• Right: Three qubit superposition
• Left: Two qubit superposition
• Push: Set the backend:
  • AER 'qasm_simulator'
  • IBMQ 'ibmqx2'
  • IBMQ 'ibmqx4'
  • Least busy IBM Q backend. Qrasp in Aer simulator mode. Qrasp in IBM Q hardware mode, with IBM Qx 4 selected. Looks much better in real life... White-and-yellow-on-blue contrast doesn't work well with cameras.

• Snazzy 'quantum calculations running' animation on the 8x8 LED display while the simulation is running or while waiting for the hardware backend to return results.
• Status and queue indicator for running against IBM Q hardware.
• Use built-in SenseHat emulator instead of hardware SenseHat.
• More...

Qrasp consists of the following scripts:

1. main_controller.py
   This script loads the required libraries, and uses the SenseHat joystick to select one of the Quantum programs.

2. Quantum program scripts
   These scripts creates and executes the quantum programs, and then calls the display script with the results. For more information about the circuits and how to construct your own, see the IBM Q Experience Beginners Guide.

   • q2_calling_sense_func.py
     Python function that creates a simple, two qubit quantum cirquit and sets up and measures each qubit in a superposition state.

                      ┌───┐┌─┐
     q0_0: |0>────────┤ H ├┤M├
              ┌───┐┌─┐└───┘└╥┘
     q0_1: |0>┤ H ├┤M├──────╫─
              └───┘└╥┘      ║
      c0_0: 0 ══════╬═══════╩═
                    ║         
      c0_1: 0 ══════╩═════════
     

   • q3_calling_sense_func.py
     Python function that creates a simple, three qubit quantum cirquit and sets up and measures each qubit in a superposition state.

                              ┌───┐┌─┐
     q1_0: |0>────────────────┤ H ├┤M├
                      ┌───┐┌─┐└───┘└╥┘
     q1_1: |0>────────┤ H ├┤M├──────╫─
              ┌───┐┌─┐└───┘└╥┘      ║
     q1_2: |0>┤ H ├┤M├──────╫───────╫─
              └───┘└╥┘      ║       ║
      c1_0: 0 ══════╬═══════╬═══════╩═
                    ║       ║         
      c1_1: 0 ══════╬═══════╩═════════
                    ║                 
      c1_2: 0 ══════╩═════════════════
     

   • bell_calling_sense_func.py
     Python function that creates a simple, two qubit quantum cirquit and sets up and measures a Bell, or entangled, state.

              ┌───┐        ┌─┐
     q2_0: |0>┤ H ├──■─────┤M├
              └───┘┌─┴─┐┌─┐└╥┘
     q2_1: |0>─────┤ X ├┤M├─╫─
                   └───┘└╥┘ ║
      c2_0: 0 ═══════════╬══╩═
                         ║    
      c2_1: 0 ═══════════╩════
     

   • GHZ_calling_sense_func.py
     Python function that creates a simple, three qubit quantum cirquit and sets up and measures an entangled GHZ state.

                                     ┌───┐             ┌───┐┌─┐
     q3_0: |0>───────────────────────┤ H ├──■──────────┤ H ├┤M├
                   ┌───┐     ┌───┐┌─┐└───┘  │          └───┘└╥┘
     q3_1: |0>─────┤ H ├──■──┤ H ├┤M├───────┼────────────────╫─
              ┌───┐└───┘┌─┴─┐└───┘└╥┘     ┌─┴─┐┌───┐┌─┐      ║
     q3_2: |0>┤ X ├─────┤ X ├──────╫──────┤ X ├┤ H ├┤M├──────╫─
              └───┘     └───┘      ║      └───┘└───┘└╥┘      ║
      c3_0: 0 ═════════════════════╬═════════════════╬═══════╩═
                                   ║                 ║         
      c3_1: 0 ═════════════════════╩═════════════════╬═════════
                                                     ║         
      c3_2: 0 ═══════════════════════════════════════╩═════════
     

3. qc_sensehat_func.py
   Using SenseHat 8x8 display to show bar graph of 2 or 3 qubit Qiskit results dictionaries.