Random Distillation Protocols in Long Baseline Telescopy

Abstract

In quantum-enhanced astronomical imaging, multiple distant apertures work together by utilizing quantum resources distributed from a central server. Our findings suggest that pre-processing the stellar light received by all telescopes can improve imaging performance without increasing resource consumption. The pre-processing leverages weak quantum measurements and modifies random-party entanglement distillation protocols from quantum information science. Intuitively, this approach allows us to collapse the stellar light that is originally coherent between all telescopes to one pair of telescopes with probability arbitrarily close to one. The central server can then distribute entanglement solely to the pair of telescopes receiving a photon, thereby enhancing the efficiency of resource utilization. We discuss two types of resources that benefit from this pre-processing: shared entanglement and a shared reference frame.

Figures (5)

• Figure 1: We compare two methods for quantum long baseline telescopy. In the top method, a source distributes entanglement to a random pair of telescopes so that it can interfere with light from a distant star. In the bottom method, the stellar photon undergoes pre-processing to localize the photon to a pair of telescopes and then the source sends entanglement to that pair.
• Figure 2: Ratio between Fisher information with quantum and classical randomness $\frac{\Vert F^{qr}\Vert}{\Vert F^{cr}\Vert}$ as a fuction of the number of rounds $D$. The solid line uses numerically optimized $\tau_j$, the dashed line uses suboptimal choice of $\tau_j = \frac{1}{2 + D - j}$ for $j$th round. The number of telescopes $M = 8$.
• Figure 3: $\gamma_D$ as a function of the number of telescopes $M$ with the numerically optimized $\tau_j$. The dot indicates the numerical calculation of optimal $\gamma_D$ when $D=70$. The solid line shows the fitted formula $\gamma_D=1/(M-1)$.
• Figure 4: (a) $\gamma_D$ as a function of the number of measurement rounds $D$. (b) Ratio between Fisher information per terrestrial photon with quantum and classical randomness $\frac{\Vert F^{qr}\Vert}{\Vert F^{cr}\Vert}$ as a fuction of the number of measurement rounds $D$. Both are calculated with the numerically optimized $\tau_j$ (solid line) and a suboptimal choice of $\tau_j=\frac{1}{2+D-j}$ (dash line). Number of telescopes $M=8$.
• Figure 5: Optimized $\tau_j$ for different number of telescopes $M=3,5,7$ when the number of measurement rounds $D=50$.

Theorems & Definitions (2)

• Theorem 1
• Theorem 2