Single-Light-Pulse Driven Compact Atom Interferometry with Measurement Induced Large Momentum Transfer

Abstract

We propose a fundamentally new design strategy of light-pulsed atom interferometry (LPAI) with a single atomic beam splitter. A traditional $π/2$-pulse Raman beam is employed to render a small momentum transfer at the initial state. After a short period of evolution during which physical relevant information can be loaded, a quantum weak measurement is applied to the internal state of the atoms. The final information will be detected from the transmission spectrum of a probe light to obviate the measurement of florescence signal. An effective amplification of the order of $10^3$ about the momentum offset is achieved in our simulation employing $Cs$ atoms with current experimental condition. Our proposal offers a cost-effective, high-accuracy measurement and readout strategy for LPAI. Furthermore, the strategy makes the physical setup much simpler and more compact offering new direction towards portable sensitive LPAI.

Figures (5)

• Figure 1: Experiment scheme. (a) Energy level diagram of experiment scheme. (b) Laser timing diagram of Ramam light and probe light. (c)-(e) Evolution of state vector in Bloch sphere, the red arrow represents the state vector, and the blue arrow represents the post-selection state.
• Figure 2: Asymmetric interference of momentum wave packets of cesium atoms at $1\mathrm{K}$. The symmetric (red), asymmetric (blue) parts and total (black) of the post-selection. The centroid of the wave packet is significantly shifted. ($\theta=\pi /4-\pi /1000$ and $\phi=0.03$)
• Figure 3: Transmission spectrum of probe light considering the Doppler effect. (a) Normalized heat map of Doppler effect with laser frequency detuning $\delta$ and post-selection parameters $\phi$. (b) Transmission spectrum with different post-selection parameters, red dotted line for $\phi=0.0005$, black solid line for $\phi=0.02$, and blue dotted line for $\phi=0.03$. The temperature $T=1K$ and $\theta=\pi /4-\pi /1000$.
• Figure 4: Results of simulation. (a) Normalized heat map of transmission spectrum of probe light with laser frequency detuning $\delta$ and post-selection parameters $\phi$. (b) Transmission spectrum with different post-selection parameters, red dotted line for $\phi=0.0005$, black solid line for $\phi=0.02$, and blue dotted line for $\phi=0.03$. (c) Relationship between spectral centroid offset (compared to frequency detuning $\delta$) and $\phi$. The temperature $T=1K$ and $\theta=\pi /4-\pi /1000$.
• Figure 5: Results of simulation. (a) Interference fringes of traditional atom interferometry adding white noise. (b) Centroid of spectrum of compact LPAI adding white noise. The signal-to-noise ratios of the two simulation scenarios are the same.