arXiv:2103.04022 · Journal of the Optical Society of America B
Quantum state preparation and one qubit logic from third-order nonlinear interactions
Francisco A. Domínguez-Serna, Karina Garay-Palmett
Abstract
We present a study on preparing and manipulating temporal-mode (TM) qubits based on third-order nonlinear interactions. Specifically, we consider the process of frequency conversion via difference frequency generation. To prepare a qubit, we aim to use Gaussian input states to a nonlinear waveguide. The coupling between the input state and a specific TM is maximized, obtaining qubits prepared with fidelities close to one. TMs evolve linearly within the medium; therefore, it is possible to define rotations around any axis contained in the x y plane, allowing spanning the full Bloch sphere in two steps. Particularly, we present a method to obtain any of the Pauli quantum gates by varying geometric or user-accessible parameters in a given experimental configuration when time-ordering effects are ignored. Our study allows for experimentally feasible proposals capable of controllable arbitrary qubit transformations.