Frequently Asked Questions

Interested in exploring QSim? All you need to do is, send a mail to qcworkbench[at]cdac[dot]in. That’s it! You will be receiving a mail once the account is created with the details to access the service. Just login and experience the Quantum Simulation right in the browser.

Code Editor:

After login, you will land on the “Build Circuits” page, which will allow you to write your own Qiskit program and hit enter at the end of each line to see the instant circuit generation. The Python code editor comes with features such as Autocompletion, search and replace, jump to line, keyboard shortcuts and syntax highlighting to enable users to write programs faster.

Noise Parameters:

One of the key benefit of QC Workbench is the ability to induce noise parameters and that can be easily done by clicking the “Noise Parameters” tab in the right sidebar. The user friendly text fields allows to customize the parameter values and see those updates in real-time in the code editor. The parameter value ‘1’ means “Zero Noise” and ‘0’ being “Very Noisy”.

Simulation Options

Choose to plot your program, enable partition or carry out some Initializations using the options located under “Simulation Options” tab in the right sidebar.

Submit for Simulation

Done with your coding, just click on “Run Circuit” button located at the top to submit your program for simulation. Lookout for the Job Id/Simulation Id, returned via the green notification at the bottom right corner of the page, which is then used for monitoring the progress of the job. The red notification means the program has some errors/the application has an issue in accepting your request.

Checking Simulations status

Click on “Simulations” tab or link on the left sidebar to view the list of Simulations submited, and its status. Drill down by clicking on the Job row to view Outputs, errors and circuits submitted.

Examples/Pre-loaded programs

Click on the “Examples” link to view all the available programs and algorithms. Select any program to load it into the editor and start customizing it to your need.

Upon hitting Shift + Enter in the code editor will trigger the instant circuit generator module. For example, to add a ‘h’ gate, you need to  type the following line:

qc.h(q[0])

After typing the line, hit Shift + Enter to trigger the circuit generator.

Why Shift + Enter? In the earlier version, hitting Enter was triggering the instant circuit generation module which is now replaced with Shift + Enter for a good reason. Enter key will trigger the linting module and hitting Shift + Enter will trigger circuit generation module.

That’s a limitation in version 1.0 for a reason.

Calling execute() function within anoter function will make the circuit generation to fail. Yes, this could be termed as a major limitation, but we are in the work to fix the issue. Well, the limitation is for a reason – executing the entire Python code  could be one of the way to generate the circuit, but it comes at a cost of time (because we supposed to generate Instant circuit isn’t?). So executing the entire Python code is not a viable solution for generating the instant circuit. In order to reduce the time taken for circuit generation, our Python parser does some heavy lifting job to identify and trim the execution part of the code (which usually takes long time to execute); which intern is executed to print the Quantum Circuit instantly (wait! at least few seconds to be precise).

Finally, not the right justification to defend the bug, but yes the fix will be made available soon.

Look out for the measure() line with blue background in the editor. This red square The blue background represents the line that contains measure() functions. In order to add measurement to the statement, you need to simply right-click on the line and select the desired measurements.

The version 1.0 supports Single Qubit, Ensemble and Expectation measurements. So you will not find Bell basis measurement option in the Context menu (when right clicked on the line that contains measure() function). However, this does not prevent you from writing your code in the editor with Bell basis measurement. The dm_simulator supports Bell basis and the simulation will just run fine, only that the GUI does not support in this version.

At present, only the Bell basis measurement and Ensemble measurement supports Plotting.