Entangling atoms for quantum metrology
Abstract/Contents
- Abstract
- Atomic sensors, such as atomic clocks and atom interferometers, have to date achieved very precise measurements of various quantities such as time, acceleration, gravitational fields and distances. However they currently use coherent (or unentangled) states of atoms, which imply that their precisions are limited by the standard quantum limit and their precision scales as $\sqrt{N}$ where $N$ is the number of atoms being used in the sensor. However this limit of these sensors can be reduced by using atoms that are in an entangled states. This work's main focus is on the creation of specific type of entangled states known as spin-squeezed states. The creation of a 20dB spin-squeezed state an ensemble of ultracold $^{87}$Rb atoms using a cavity-mediated light-atom interaction is demonstrated, with which proof-of-principle metrology is performed. More specifically, a tipping measurement resolving more than 18dB beyond the standard quantum limit and a clock measurement with a quantum enhancement of over 10dB are shown. The single-shot phase resolution of the apparatus of 147 $\mu rad$ achieved is the most precise to have been shown to date. In addition, preliminary results in which retention of squeezing of in free-space for over 1ms are discussed. Another experiment showing a ``quantum phase magnification'' method is also implemented. This method allows for entanglement-enhanced measurements without low-noise detection. We perform squeezed-state metrology 8dB below the standard quantum limit with a detection system that has a noise floor of 10dB above the standard quantum limit. Finally, the highly non classical nature of the squeezed states created is discussed, and the collective measurements of our state showing Bell correlations significant to 124 standard deviations are presented.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2017 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Krishnakumar, Rajiv |
|---|---|
| Associated with | Stanford University, Department of Applied Physics. |
| Primary advisor | Kasevich, Mark A |
| Thesis advisor | Kasevich, Mark A |
| Thesis advisor | Hogan, Jason |
| Thesis advisor | Safavi-Naeini, Amir H |
| Advisor | Hogan, Jason |
| Advisor | Safavi-Naeini, Amir H |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Rajiv Krishnakumar. |
|---|---|
| Note | Submitted to the Department of Applied Physics. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2017. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2017 by Rajiv Krishnakumar
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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