Many-body strategies for multiqubit gates: Quantum control through Krawtchouk-chain dynamics

Koen Groenland, Kareljan Schoutens
2018 Physical Review A  
We propose a strategy for engineering multi-qubit quantum gates. As a first step, it employs an eigengate to map states in the computational basis to eigenstates of a suitable many-body Hamiltonian. The second step employs resonant driving to enforce a transition between a single pair of eigenstates, leaving all others unchanged. The procedure is completed by mapping back to the computational basis. We demonstrate the strategy for the case of a linear array with an even number N of qubits, with
more » ... r N of qubits, with specific XX+YY couplings between nearest neighbors. For this so-called Krawtchouk chain, a 2-body driving term leads to the iSWAP$_N$ gate, which we numerically test for N = 4 and 6.
doi:10.1103/physreva.97.042321 fatcat:6p3pzivtvjemhlwday6xhvesfi