Learning Forum

[marinella.guzman]

How to simulate a Hadamard gate using qInterconnect? I am trying to learn qInterconnect and first I wanted to see if I can use it to analyze a simple hadamard gate using a directional coupler. However, every time I try to run it, I get an error saying that the input state does not exist in the created Hilbert space. How do i fix this? 

 

For context, this is the code I am trying to run:

 

import sys,os

from qinterconnect.solver import QSolver

os.chdir(os.path.dirname(os.path.abspath(__file__)))

nlsparams = {
              "mode_per_channel": 1,
              "nchannel": 2,
              "interconnect_file": "Trial.icp",
              "circuit": "Comp_DC",
              "input_ports": ["port 1", "port 2"],
              "output_ports": ["port 3", "port 4"],
              "nmax":2,
              "input_dims": [2,2],
              "ket_in":{
                    (0, 1): [1,0],
                    (1, 0): [1,0]                    
                        },
              "ket_out":{
                    (0,1): [0.707,0],
                    (1,0): [0.707,0]                    
                        },
              "measurement_mask":[1,0],                         
        }

        

nls = QSolver(**nlsparams)
success_prob=nls.run()

print(success_prob)
print('Final Density Matrix:')
print(nls.rho_final.tidyup(atol=1e-3))

[Artemis Karvounis]

Hello,

thank you for contacting us.

Well, you need to define properly the measurement mask. Therefore you need to modify your script in the following way:

Instead of  "measurement_mask":[1,0] you need to write:    "measurement_mask":[100,1]

More specifically, the measurement_mask is a required parameter in the dictionary of the simulation parameters. You may find more details on the following link: https://optics.ansys.com/hc/en-us/articles/7369338471443-qINTERCONNECT-User-Guide 

Kind regards,

Artemis