Semiconductor Quantum Dot Quantum Repeater

The concept of quantum repeaters was put forward by Briegel et al.in 1998.It is used to solve the problem of distributing long-distance channels.Nowadays classic repeater plays an important role in our communication.We know that classical information can be transmitted through channels such as optical fiber,but the process of transmission will decay.Duan et al proposed DLCZ(Duan-Lukin-Cirac-Zoller)protocol in 2001.This protocol is based on atomic systems and linear optics,implementing a quantum repeater scheme.Quantum repeaters can be used to solve remote distance and high fidelity communication problems.For instance,it can achieve Quantum teleportation.Quantum communication,Quantum entanglement distribution.In this thesis,after attempt to many methods,we present a quantum repeater protocol based on double quantum dot entanglement system and non-Bell measurement.This scheme does not involve the measurement of any photo-subsystem.At the same time,the implementation of this non-Bell measurement is much easier than Bell's measurement.Meanwhile,we proved that every 4 pairs of double quantum dots is a entanglement periodic,when we choose the initial state as singlet state.This thesis is divided into 5 chapters.Chapter 1:we introduce the background and development history of quantum repeaters.Chapter 2:We introduce the knowledge of the double quantum dot system and how to prepare the singlet state using double quantum dots.Chapter 3:We introduce three years of trying to use the decoherence scheme,the equivalent measurement effect to 'implement' the entanglement swapping.As well as,We analyze and summarize every scenario.Chapter 4:We introduce the use of the Cavity QED method in the large detuned case,analytically derived based on non-Bell measurements to achieve solid-state quantum devices-quantum repeaters.Chapter 5:I have made a summary and outlook on the work,which I have done in the past three years.