[Paper Review] Reconfigurable synthesizer for quantum information processing of high-dimensional entangled photons

Ohad Lib, Kfir Sulimany+1 more|arXiv (Cornell University)|Aug 4, 2021

Quantum Information and Cryptography42 references4 citations

TL;DR

This paper introduces a reconfigurable photonic processor based on multi-plane light conversion (MPLC) for quantum information processing of high-dimensional entangled photons. By leveraging MPLC’s ability to control hundreds of spatial modes, the authors demonstrate four key quantum tasks—entanglement certification, tailored two-photon interference, arbitrary state transformations, and mode conversion—on the same hardware, establishing MPLC as a scalable, flexible platform for future quantum technologies.

ABSTRACT

High-dimensional entangled photons are a key resource for advanced quantum information processing. Efficient processing of high-dimensional entangled photons requires the ability to synthesize their state using general unitary transformations. The leading technology for processing photons in high-dimensions is integrated multiport interferometers. However, such devices are incompatible with free-space and fiber-based systems, and their architecture poses significant scaling challenges. Here we unlock these limitations by demonstrating a reconfigurable processor of entangled photons that is based on multi-plane light conversion (MPLC), a technology that was recently developed for multiplexing hundreds of spatial modes for classical free-space and fiber communication. To demonstrate the flexibility of MPLC, we perform four key tasks of quantum information processing using the same MPLC hardware: entanglement certification, tailored two-photon interference, arbitrary state transformations, and mode conversion. Based on the high degree of control we obtain, we expect MPLC will become a leading platform for future quantum technologies.

Motivation & Objective

• Overcome the limitations of integrated multiport interferometers, which are incompatible with free-space and fiber systems and face scaling challenges.
• Enable efficient, reconfigurable processing of high-dimensional entangled photons for advanced quantum information tasks.
• Demonstrate that MPLC technology—originally developed for classical communications—can serve as a viable platform for quantum photonic processing.
• Achieve flexible, hardware-reconfigurable control over high-dimensional photonic states using a single device architecture.
• Establish a scalable and integrable solution for future quantum technologies requiring complex unitary transformations on high-dimensional quantum states.

Proposed method

• Utilize multi-plane light conversion (MPLC), a spatial multiplexing technology, to manipulate hundreds of spatial modes in free-space and fiber-based systems.
• Implement a reconfigurable optical setup based on MPLC to perform general unitary transformations on high-dimensional photonic states.
• Leverage the phase and amplitude control of multiple wavefronts across multiple planes to synthesize arbitrary quantum states.
• Use a single MPLC device to perform four distinct quantum information tasks without hardware reconfiguration.
• Apply the MPLC processor to generate and manipulate high-dimensional entangled photon states with high fidelity.
• Validate the processor’s functionality through quantum state tomography, interference measurements, and state transformation protocols.

Experimental results

Research questions

• RQ1 Can MPLC technology be adapted to perform reconfigurable, high-dimensional quantum state processing in free-space and fiber systems?
• RQ2 To what extent can a single MPLC-based device perform diverse quantum information tasks such as entanglement certification and tailored two-photon interference?
• RQ3 How does the scalability and control fidelity of MPLC compare to integrated multiport interferometers for high-dimensional quantum optics?
• RQ4 Can MPLC enable arbitrary unitary transformations on high-dimensional photonic states with experimental precision?
• RQ5 Is MPLC a viable platform for future large-scale quantum information processing with high-dimensional systems?

Key findings

• The MPLC-based processor successfully performed entanglement certification on high-dimensional photonic states using the same hardware.
• Tailored two-photon interference was achieved with high visibility and programmable phase control, demonstrating precise quantum interference control.
• Arbitrary unitary transformations were implemented on high-dimensional states, confirming the device’s capability for general quantum state manipulation.
• Mode conversion between different spatial modes was achieved with high fidelity, showcasing the processor’s reconfigurability.
• The same MPLC hardware performed all four quantum tasks without physical reconfiguration, proving its flexibility and reprogrammability.
• The results establish MPLC as a scalable, reconfigurable platform for future high-dimensional quantum information processing.