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Towards a Quantum Network with Atomic Ensembles


Chou, Chin-wen (2006) Towards a Quantum Network with Atomic Ensembles. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/ANAH-0961.


The experiments discussed in this thesis investigate the application of atomic ensembles in building a quantum network. Specifically, the atomic ensembles refer to cesium atoms in magneto-optical traps.

Chapter 1 gives an introduction to quantum networks, along with the difficulty in extending the range due to the optical loss of communication channels.

Chapter 2 describes the protocol proposed by Duan, Lukin, Cirac, and Zoller (DLCZ) for overcoming the limit of channel loss on scaling up a quantum network, exploiting relatively simple setups with atomic ensembles. The protocol introduces many capabilities and simplifies many tasks in quantum information processing with atoms and light.

Chapter 3 summarizes the first step in our lab toward realizing the DLCZ protocol.

In particular, we observed nonclassical correlation between two optical fields generated from one atomic ensemble.

Chapter 4 is a sidetrack apart from the DLCZ protocol. We demonstrated that the atomic ensemble can be used as a conditional source of single photons. In addition to a description of the experiment, details of the simple model we used to fit the data are also included.

Chapter 5 augments chapter 4 in that the temporal behavior of the nonclassical correlation is investigated. We found that the correlation decayed rapidly, which is a major obstacle for further implementation of the DLCZ protocol.

Chapter 6 describes our effort to fight the fast decay of correlation observed in the experiment. A theoretical model is used to better understand the source of decoherence.

Chapter 7 is the follow-up in the direction of implementing the DLCZ protocol. Two atomic ensembles located in vacuum chambers on two optical tables are entangled in a heralded fashion. The details on controlling the phases of the interferometers and data processing are elaborated.

Chapter 8 is a practical proposal on how to proceed further toward realization of the DLCZ protocol. Four atomic ensembles are involved in the proposed setup, which merely requires relative phase stability.

Chapter 9 concludes the thesis and provides several possible directions toward building a large-scale quantum network through the DLCZ protocol.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:DLCZ; quantum entanglement; quantum repeater
Degree Grantor:California Institute of Technology
Division:Physics, Mathematics and Astronomy
Major Option:Physics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Kimble, H. Jeff
Thesis Committee:
  • Kimble, H. Jeff (chair)
  • Preskill, John P.
  • Vahala, Kerry J.
  • Painter, Oskar J.
  • Blatt, Rainer
Defense Date:22 May 2006
Record Number:CaltechETD:etd-05252006-185918
Persistent URL:
Chou, Chin-wen0000-0001-7759-823X
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:2059
Deposited By: Imported from ETD-db
Deposited On:31 May 2006
Last Modified:08 Nov 2023 18:42

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