The Theory Research About Quantum Operation On Quantum Dot

With the development of nanometer materials science and experimental technology, a series of iconic research progress have been made in solid quantum computation and quantum information in recent years, driven by the accumulation of study and the related theoretical research on the atom and molecule. The quantum dot(QD) system is integratable and extensible, which is closely related to the semiconductor photonics and technology. Cavity Quantum Electrodynamics(CQED) is one of the most promising technologies to implement quantum information process(QIP) device. Therefore, the quantum operation about cavity-QD system is very important to construct quantum computer.This paper discuss the computation of effective Hamiltonian and the substitution of annihilation operator for unitary transformation, and then design two new cavityQD systems based on the study about classical systems. In the interaction picture, we introduce the linearly dependent bosonic modes to take unitary transformation on the time-dependent Hamiltonian, and get the effective Hamiltonian using rotating wave approximation(RWA) under the condition of large detuning. Eventually, the phase gate is obtained and we generalize this protocol to N-cavity system.Quantum phase gates are prepared by controlling the initial state of cavity and quantum dot, and we generalize the protocol to N-qubit. Meanwhile, because the system is not excited during the whole process, our protocol is immune to the decoherence effect induced by atomic spontaneous emission or cavity decay.These new protocols have been proposed in the new designed quantum systems, which are feasible to prepare quantum phase gate and implement solid quantum device.