QEC Circuit Transform
=====================

Quantag Studio provides a powerful feature to automatically wrap your ideal quantum circuits (QASM) into state-of-the-art Quantum Error Correction (QEC) codes and simulate realistic noise models. 
This feature is powered by a high-performance backend running NVIDIA CUDA-Q QEC.

When you open a .qasm file in the active editor, you can trigger this functionality via the Command Palette by selecting **Quantag Studio: QEC Circuit Transform**.

This opens a dedicated Webview panel with an interactive configuration interface.

.. image:: images/qec1.png
   :alt: Screenshot 1
   :width: 100%
   :align: center

The interface allows you to configure the following parameters:

* **QEC Code Geometry**: Select the error correction code to apply, such as Steane (7-qubit) or Surface codes of different distances.
* **Output Type**: Choose whether to output the physical circuit or the Detector Error Model (DEM).
* **Noise Probability**: An interactive slider to set the depolarizing error rate applied to physical gates during the simulation.

After configuring the parameters and pressing **Transform Circuit**, the extension sends your circuit to the secure backend. A new editor tab will open with the results.

If you selected the **Physical Circuit** output type, the engine analyzes the selected QEC code and returns a commented QASM file showing data qubits, ancilla qubits, and stabilizers.

.. image:: images/qec2.png
   :alt: Screenshot 2
   :width: 100%
   :align: center

If you selected the **Detector Error Model (DEM)** output type, the backend injects the specified depolarization noise into all memory round operations and evaluates the error graph. The output provides a summary of the raw matrices (exported for modern decoders like TensorRT or PyMatching).

.. image:: images/qec3.png
   :alt: Screenshot 3
   :width: 100%
   :align: center