# Bayesian feedback control of a two-atom spin-state in an atom-cavity system.

@article{Brakhane2012BayesianFC, title={Bayesian feedback control of a two-atom spin-state in an atom-cavity system.}, author={Stefan Brakhane and Wolfgang Alt and Tobias Kampschulte and Miguel Martinez-Dorantes and Ren{\'e} Reimann and Seokchan Yoon and Artur Widera and Dieter Meschede}, journal={Physical review letters}, year={2012}, volume={109 17}, pages={ 173601 } }

We experimentally demonstrate real-time feedback control of the joint spin-state of two neutral cesium atoms inside a high finesse optical cavity. The quantum states are discriminated by their different cavity transmission levels. A Bayesian update formalism is used to estimate state occupation probabilities as well as transition rates. We stabilize the balanced two-atom mixed state, which is deterministically inaccessible, via feedback control and find very good agreement with Monte Carlo…

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## References

SHOWING 1-10 OF 10 REFERENCES

### Quantum computation and quantum information

- PhysicsMathematical Structures in Computer Science
- 2007

This special issue of Mathematical Structures in Computer Science contains several contributions related to the modern field of Quantum Information and Quantum Computing. The first two papers deal…

### Quantum computation and quantum information

- Physics, Computer Science
- 2000

This chapter discusses quantum information theory, public-key cryptography and the RSA cryptosystem, and the proof of Lieb's theorem.

### Applied Physics B: Lasers and Optics

- Physics
- 2003

To clarify the advantages of Cr:Nd:YAG ceramics rods in solar-pumped lasers, a fused silica light guide with rectangular cross-section is coupled to a compound V-shaped cavity within which a 7 mm…

### Data analysis : a Bayesian tutorial

- Mathematics
- 1996

This tutorial jumps right in to the power ofparameter estimation without dragging you through the basic concepts of parameter estimation.

### Nature Phys

- 8, 292
- 2012

### * Electronic address: brakhane@iap.uni-bonn

### Physics Today 57

- 38
- 2004

### Nature (London) 475

- 210 (2011). PRL 109, 173601
- 2012

### New J

- Phys. 10, 073023
- 2008