Inequality constraints in variational quantum circuits with qudits

Understand

Quantum optimization is emerging as a prominent candidate for exploiting the capabilities of near-term quantum devices.

• Many application-relevant optimization tasks require the inclusion of inequality constraints, usually handled by enlarging the Hilbert space through the addition of slack variables.
• This approach, however, requires significant additional resources especially when considering multiple constraints.
• Here, we study an alternative direct implementation of these constraints within the QAOA algorithm, achieved using qudit-SUM gates, and compare it to the slack variable method generalized to qudits.