This book highlights the novel research in quantum memory networking, especially quantum memories based on cold atomic ensembles. After discussing the frontiers of quantum networking research and building a DLCZ-type quantum memory with cold atomic ensemble, the author develops the ring cavity enhanced quantum memory and demonstrates a filter-free quantum memory, which significantly improves the photon-atom entanglement. The author then realizes for the first time the GHZ-type entanglement of three separate quantum memories, a building block of 2D quantum repeaters and quantum networks. The author also combines quantum memories and time-resolved measurements, and reports the first multiple interference of three single photons with different colors. The book is of good reference value for graduate students, researchers, and technical personnel in quantum information sciences.

Autorentext
Dr. Bo Jing Bo Jing received his PhD from the University of Science and Technology of China in 2019. His research mainly focused on quantum networks with quantum memories, covering highly retrieved quantum memories based on cold atomic ensembles, entanglement of multiple quantum memories, and multi-photon interference. His findings were published in Nature, Nature Photonics, and Physical Review Letters, etc.

Inhalt

Chapter 1 Introduction

1.

1.1. Quantum teleportation 1.2. Connection of two quantum nodes

1.3. Connection of multiple quantum nodes

1.4. Physical realization of quantum network 1.5. Current state of the art for quantum networks

1.6. Thesis structure

Chapter 2 Interaction of single photons and atomic ensembles

2.

2.1. Photon-atom interaction: classical description 2.2. Cavity-enhanced photon-atom interaction: quantum description

2.3. Brief summary

Chapter 3 Preparation of cold atomic ensembles

3.

3.1. Vacuum 3.2. Lasers

3.3. Magnetic field

3.4. Magnetic optical trap 3.5. Polarization gradient cooling

3.6. Cold atomic optical depth and temperature

3.7. Further cooling of cold atoms 3.8. Brief summary

Chapter 4 Highly retrieved quantum memory

4.

4.1. Backgroud 4.2. Principle of DLCZ-type quantum memory

4.3. DLCZ-type quantum memory in free space

4.4. DLCZ-type quanutm memory in a ring cavity

4.5. Quantum memories with atomic initial state

4.6. Brief summary

Chapter 5 Entanglement of three cold atomic ensembles

5.

5.1. Background 5.2. Entanglement between single photons and cold atomic ensembles

5.3. Entagnlement between two cold atomic ensembles 5.4. Hybrid entanglement...