Implementation of Grover's algorithm on the IBMQ: constraints and error assessment
Asma Eldridi, Amor Gueddana, Vasudevan Lakshminarayanan · 2021
We use the IBMQ machine to implement a quantum database circuit. The database is made of a single multi- column table with multiple superposed records using Toffoli, CNOT and single quantum qubit gates. We present an optimized quantum circuit which allows us to select an item from the table, according to a specific oracle. Our circuit is based only on a single auxiliary qubit to perform the Selective Inversion (SI) and the Inversion Around the Average (IAA), which constitute the Grover operator. We analyze the difference between the generated transpired circuits while executing the original circuit on different IBMQ machines, namely the Melbourne and Athens quantum machines. We discuss the physical constraints causing the difference between the simulation on the composer and the executions of the circuits on the real IBMQ devices.