Quantum State Preparation on a Superconducting Qubit Lattice

Efficient quantum state preparation is integral to both encoding quantum information and simulating quantum systems. As quantum systems scale up, preparation of a desired quantum state within the coherence-time limit of the comprising qubits becomes increasingly difficult to achieve. We have developed a 21-qubit superconducting quantum processor consisting of a 3x3 array of 9 lattice qubits (qubits containing readable quantum information) and 12 coupler qubits (qubits that mediate interactions between lattice sites). Our platform uses asymmetric tunable transmon qubits, which natively emulate a Bose-Hubbard Hamiltonian, as well as precision temporal control to allow customization of the lattice Hamiltonian. Additionally, this platform allows for precise control of single and two-qubit gates, expanding our capabilities to include implementation near term quantum algorithms on the lattice. Although the primary application of near-term algorithms such as VQE, ASP, QAOA has been towards optimization problems, these same techniques can be used to prepare the ground state of a designed or induced Hamiltonian [1]. In this talk, we will discuss applications of near-term quantum algorithms to preparing interesting condensed matter states on a superconducting quantum processor.



References:

[1] Vladimir Kremenetski et al. “Quantum Alternating Operator Ansatz (QAOA) Phase Diagrams and Applications for Quantum Chemistry”. In: (2021)