A quantum circuit must be translated into a form which can be executed on a quantum computer with limited size and connectivity. If there are multiple ways for a given circuit to be mapped onto a quantum chip, which one should we select? In this lecture, Carmen G. Almudever will detail the necessary steps in this selection; decomposition, optimisation, placement, routing, fault-tolerant synthesis and scheduling.

Main takeaways

• Many quantum algorithms involve unitary gates which must be decomposed into single- and two-qubit gates in order to be executed.
• The most popular family of operations for decomposition is {H,T,CNOT}, because these operations can, in many quantum error-correcting codes, be executed easily.
• We must then decompose these operations further, into those that can be executed directly on the chip, also taking into account connectivity and time constraints.