Quantum Solution for Telescope Arrays

F. De Martini, G. Denardo, Anton Zeilinger

Yujie Zhang, Yunkai Wang, Wilson Wu +1 more

Conventional stellar interferometry reconstructs incoherent sources from pairwise mutual coherences between telescopes. Are such pairwise measurements sufficient for quantum-limited subdiffraction imaging with a telescope array? We show that for generic image-moment estimation, they are not. We consider weak incoherent light from a generic extended source observed by an array of telescopes, each supporting a single optical mode. For an N-telescope array, we derive the quantum Fisher information (QFI) scaling of image moments up to the cutoff 2N-2 and prove that arbitrary measurements restricted to telescope pairs attain the full-array QFI scaling only up to second order. Thus, estimating higher-order moments at the quantum limit requires genuinely multi-telescope interference. Inspired by spatial-mode demultiplexing (SPADE) from single-aperture subdiffraction imaging, we construct array-SPADE measurements that attain the optimal QFI scaling up to the finite-array cutoff. Finally, we show that these measurements can, in principle, be embedded in ancilla- and memory-assisted quantum-network architectures for long-baseline telescopy.

Daniel Gottesman, Thomas D. Jennewein, Sarah Croke +1 more

Interferometry among telescope arrays has become a standard technique in astronomy. We discuss using quantum repeaters to increase the baseline length, and therefore resolving power, of telescope arrays at optical observing frequencies.

Dainis Dravins

Jian Leng, Yi-Xin Shen, Zhou‐Kai Cao +1 more

Angular localization of remote optical objects is a fundamental challenge in fields such as remote sensing and astrometry. We propose the piecemeal method for a telescope array, with explicit formulas showing its key advantages strictly: higher precision, efficiency, and robustness, which are further confirmed by numerical simulations. Specifically, our method achieves a 10 4 precision improvement with 10 5 photon number reduction compared to existing telescope arrays, and achieves precision improvements of 10 3 and 10 2 over the Gaia telescope and the ultimate quantum limit for incoherent imaging, respectively, under comparable photon numbers. We have also presented a reference-object-based implementation framework for our method that seamlessly integrates with existing optical interferometric systems.

J. I. Cirac, Harry J. Kimble