The role of tunneling noise in triple spin exchange qubits

Abstract

The qubit is the basic unit of quantum information. Qubits are essential to the implementation of quantum computing. Quantum computation are widely applied in elds such as cybersecurity, cryptography, arti cial intelligence and machine learning. Therefore, a research in the implementation of a qubit is essential. In this project, the effects of 1/f tunneling noise in a triple spin exchange qubit operating at the sweet spot is being investigated. The Hubbard model is used to approximate the behaviour of electrons in the triple spin exchange qubit. The Hamiltonian of the Hubbard model for the system was calculated using a particular basis of the electron states. The existence of a double sweet spot is then presented in the Hamiltonian. The generation of 1/f noise is then studied and implemented into the tunnelling parameter of the Hamiltonian. Working on a particular sweet spot, the evolution of qubit over time was simulated. The loss of phase information of the qubit was then demonstrated from the results of the simulation. The dephasing is then compared to a free induction decay model and compared for di erent values of tunneling parameter and different order of noise spectrum. The process is repeated for both correlated and uncorrelated noises in both tunnelling parameters.