M.Sc Thesis

M.Sc StudentAlcobi Enav
SubjectDecoherence in Adiabatic Passage
DepartmentDepartment of Electrical and Computer Engineering
Supervisors DR. Yuval Oreg
Full Thesis textFull thesis text - English Version


Future quantum computers are based on manipulation of quantum bits (qubits), where a qubit is a coherent superposition of states "0" and "1". Researchers suggested to use the electron spin as the basic qubit, since it can be in two definite states, for example ‘up’ for “0” and ‘down’ for “1”. For a successful operation of such computers, spins should be manipulated coherently, with a long enough coherence time. In this thesis, we describe the Coherently Transfer Adiabatic Passage (CTAP) method; embodied by making use of a few quantum dots. In this method, a certain sequence of time dependent adiabatic pulses on the metallic gates defining the quantum dot controls the electron position. The advantage of the CTAP method is in its ability to transfer an electron between two distant dots so that the probability to find it on its way is minimal. Hence, minimizing decoherence due to interaction with the environment on the way. We describe a novel way to quantify and measure the amount of decoherence in this class of systems using a novel quantum mechanical interferometer.