Improved Mapping of Quantum Circuits to IBM QX Architectures
Sprache des Titels:
Quantum computers are becoming a reality today
due to the rapid progress made by researchers in the last years.
In the process of building quantum computers, IBM has developed several versions starting from 5-qubit architectures like
IBM QX2 and IBM QX4 to larger 16- or 20-qubit architectures.
These architectures support arbitrary rotations of a single qubit
and a controlled negation (CNOT) involving two qubits. The two
qubit operations come with added coupling-map restrictions that
only allow specific physical qubits to be the control and target
qubits of the operation. In order to execute a quantum circuit on
the IBM QX architecture, CNOT gates must satisfy the so-called
coupling constraints of the architecture.
Previous works addressed this issue with the objective of
reducing the number of gates and the circuit depth. However,
in this work we show that further improvements are possible. To
this end, we present a general approach for further improving
the number of gate operations and depth of the mapped circuit.
The proposed approach encompasses the selection of physical
qubits, determining initial and local permutations efficiently to
obtain the final circuit mapped to the given IBM QX architecture.
Through experiments improvements are observed over existing
methods in terms of the number of gates and circuit depth.
Sprache der Kurzfassung:
IEEE Transactions on Computer Aided Design of Integrated Circuits and Systems (TCAD)