Quantum Resources Required for GKP Qubits
Qubits are fundamental units for quantum computation. Photonics is a promising physical medium to realize large-scale quantum computation. One proposal to realize photonic qubits was proposed by Gottesman, Kitaev and Preskill (GKP). Here, the logical qubit is encoded into states of a bosonic mode or a quantum harmonic oscillator. It is expected that such a procedure will lead to a better quality and number of qubits. Very recently, it was shown that these GKP qubits along with Gaussian operations that can be constructed from squeeze operators, displacements, interferometers, phase shifters, and homodyne measurements are sufficient for universal fault-tolerant quantum computation. The GKP qubits could play an important role in many applications of quantum computation using continuous-variable systems. The aim of this project is to determine the resources required for producing GKP qubits using squeezed displaced states, interferometers, and photon-number-resolving measurements.