How to represent two gates addition on Qiskit composer we can do it in python code by using qiskit library but I would like to visually see how addition of two operators look like in composer.

I am currently working on VQLS Algorithm and we have to decompose given matrix into linear combination of unitary matrices. I want to see that in Qiskit composer.


  • 1
    $\begingroup$ Would you consider writing it in code and using decomposition there before printing the circuit? $\endgroup$
    – 3yakuya
    Commented Mar 24, 2023 at 15:09
  • $\begingroup$ Can you give some sample code for addition operator. $\endgroup$ Commented Mar 26, 2023 at 1:52
  • $\begingroup$ Not sure I understand, but I assume you mean how to combine two operators into one? You can use compose for that: qiskit.org/documentation/stubs/… What is more, you can decompose any operator (as long as it's an actual quantum operator) into a series of basic operators using either decompose qiskit.org/documentation/stubs/… or transpiler qiskit.org/documentation/apidoc/transpiler.html $\endgroup$
    – 3yakuya
    Commented Mar 30, 2023 at 13:47
  • $\begingroup$ I mean when I decompose a non unitary matrix into series pauli base matrices like ( A = aX + bY + cZ ) where X,Y,Z are pauli basis and I want to visually show my matrices decomposition on composer and if I keep my operators side by side it will do multiplication..My question is How to show it on composer? should i create a custom gate or How ? and one more question is how to show my coefficient values along with my operator ? any QISKIT Composer snip will help.. Thanks in Advance $\endgroup$ Commented Apr 3, 2023 at 13:48

1 Answer 1


Assuming you mean IBM Quantum composer, it allows OpenQASM 2.0 as input. You could synthesises your circuit and them exported as OpenQASM 2.0:

from qiskit import QuantumCircuit, transpile
matrix = [[0, 0, 0, 1],
          [0, 0, 1, 0],
          [1, 0, 0, 0],
          [0, 1, 0, 0]]
circuit = QuantumCircuit(2)
circuit.unitary(matrix, [0, 1])

Then, take my_circuit.qasm and import it in IBM Quantum Composer: screenshot of IBM Quantum Composer


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