qudit-sim 0.1.0

Multi-qudit system simulation and analysis

Pulse simulation for qudits

This repository contains a tool for extracting effective Hamiltonians / gate unitaries of arbitrary microwave pulses applied to a system of coupled d-level quantum oscillators (qudits). Its intended usage is as a base for prototyping new pulse sequences that implement custom quantum gates involving more than two oscillator levels.

Most of the heavy-lifting is done by QuTiP through its Schrodinger equation solver (sesolve). The main functions of this tool are to prepare the Hamiltonian object passed to sesolve from the input parameters, and to interpret the result of the simulation.

The tool takes the following input:

• Base (qubit) frequencies and anharmonicities of the oscillators
• Transverse coupling coefficients between the qudits
• (Classical) crosstalk matrix between the qudits
• Carrier frequencies and envelope functions of the drive pulses

The first two items are given in the format used to specify the IBM Quantum machines. The crosstalk matrix determines how a drive pulse applied to a qudit is felt by another qudit.

As the focus of the tool is on prototyping rather than performing an accurate simulation, the tool currently assumes a simple model of the system. In particular, incoherent effects (qudit relaxation, depolarization, etc.) are not considered. The full Hamiltonian can be found in the docstring of make_hamiltonian_components in pulse_sim.py.

Check out demo.ipynb for example usage.