Universal interference-based construction of Gaussian operations in hybrid quantum systems

• Main Authors: Zhang, Mengzhen, Chowdhury, Shoumik, Jiang, Liang
• Format: Journal Article
• Language: English
• Published: 15-12-2021
• Subjects: Physics - Quantum Physics
• DOI: 10.48550/arxiv.2112.08208

Beam-splitter operations are an indispensable resource for processing quantum
information encoded in bosonic modes. However, in hybrid quantum systems, it
can be challenging to implement reliable beam-splitters between two distinct
bosonic modes due to various experimental imperfections. Without
beam-splitters, realizing arbitrary Gaussian operations between bosonic modes
can become highly non-trivial or even infeasible. In this work, we develop
novel interference-based protocols for engineering Gaussian operations in
multi-mode hybrid bosonic systems without requiring beam-splitters.
Specifically, for a given generic multi-mode Gaussian unitary coupler, we
demonstrate a universal scheme for constructing Gaussian operations on a
desired subset of bosonic modes, requiring only multiple uses of the given
coupler interleaved with single-mode Gaussian unitaries. Our results provide
efficient construction of operations crucial to quantum information science and
are derived from fundamental physical properties of bosonic systems. The
proposed scheme is thus widely applicable to existing platforms and couplers,
with the exception of certain edge cases. We introduce a systematic approach to
identify and treat these edge cases by utilizing a novel intrinsically
invariant structure associated with our interference-based construction.