In a quiet lab at The Hong Kong Polytechnic University (PolyU), a team of researchers has achieved something that could very well define a new era in technology. They have developed a quantum microprocessor chip with the potential to push the boundaries of what’s computationally possible, particularly in the challenging field of quantum chemistry. This breakthrough not only showcases the power of quantum computing but also offers a glimpse into a future where classical computers’ limitations can finally be overcome.
Quantum versus classical computing
To grasp the significance of PolyU’s achievement, one must first understand the concept of quantum entanglement and how it fundamentally differs from classical computing. Consider the kaleidoscope metaphor. Kaleidoscopes create infinitely diverse yet orderly patterns using a limited number of colored glass beads, mirror-dividing walls, and light. Each rotation of the kaleidoscope produces a new, unique spectacle of fleeting colors and shapes, none of which can be precisely reversed. While the same elements might replicate some patterns, they are never identical.
In a similar way, quantum computing doesn’t seek to guess the state of any given particle but rather uses mathematical models to understand how the interactions among many particles create patterns known as quantum correlations. The result of a quantum computing operation is a probability—a likelihood that a certain configuration will emerge, akin to stopping the kaleidoscope at a particular moment and capturing the pattern within.
Simulating large molecules has long posed a significant challenge in computational chemistry due to the intricate quantum mechanical properties that must be modeled. Classical computers struggle with these tasks because the complexity of these simulations increases exponentially with the size of the molecule. To accurately model electron interactions and correlations within a molecule requires immense computational power, far beyond what classical methods can typically handle. As a result, traditional approaches often rely on approximations, leading to less precise simulations.
Inside PolyU’s quantum microprocessor
The quantum microprocessor developed by PolyU is a game changer in this regard. By leveraging the unique properties of quantum mechanics, such as superposition and entanglement, this microprocessor can simulate the quantum states of large, complex molecules with an accuracy and efficiency that was previously unthinkable. The improvement is more transformative than incremental—scientists could soon conduct simulations that were once beyond reach, potentially leading to faster and more accurate drug discoveries, and the development of innovative new materials.
The research team, led by professor Liu Ai-qun, chair professor of quantum engineering and science and director of the Institute for Quantum Technology (IQT), alongside Zhu Huihui, postdoctoral research fellow at PolyU’s department of electrical and electronic engineering, has provided initial insights into the capabilities of this quantum microprocessor. The chip, developed with collaborators from institutions like Singapore’s Nanyang Technological University (NTU), City University of Hong Kong (CityU), and Chalmers University of Technology in Sweden, employs a sophisticated theoretical model using a linear photonic network and squeezed vacuum quantum light sources to simulate molecular vibronic spectra.
This 16-qubit quantum microprocessor chip is not just a theoretical milestone but a practical one, fully integrated into a single chip with a complete system. This system includes the hardware integration of optical-electrical-thermal packaging for the quantum photonic microprocessor chip, an electrical control module, and software development for device drivers and a user interface. The underlying quantum algorithms are fully programmable, offering a fundamental building block for further applications in quantum computing.
The practical implications of PolyU’s quantum microprocessor are vast, especially for industries reliant on molecular simulations. Pharmaceutical companies, for instance, could use this technology to speed up drug discovery, enabling them to explore a broader range of molecular interactions at speeds unattainable by classical computers. Similarly, the development of new materials, such as more efficient catalysts or stronger polymers, could see significant advancements due to the precise simulations made possible by this quantum microprocessor.
Taking a quantum leap
PolyU’s accomplishment is part of a broader surge in quantum computing R&D. In the US, for example, the Argonne National Laboratory is focused on developing quantum architectures that enhance qubit coherence and stability, aiming to build more reliable quantum systems that can be scaled for various tasks. Meanwhile, researchers at the University of Rhode Island are creating modular quantum processors designed to perform a wider range of quantum tasks with greater flexibility and reliability.
While Argonne and Rhode Island’s research lays crucial groundwork for broader quantum advancements, PolyU’s quantum microprocessor is uniquely geared toward addressing the intricate challenges of simulating complex molecular structures, marking a critical contribution to the field of quantum computing.
Looking ahead, the implications of PolyU’s quantum microprocessor are both exciting and far-reaching. The next phase of research at PolyU aims to scale up the microprocessor and tackle even more intricate applications. The team envisions a future where quantum computing becomes a fundamental tool in scientific research and industry, capable of solving problems once considered insurmountable.
“Our research is inspired by the potential real-world impact of quantum simulation technologies. In the next phase of our work, we aim to scale up the microprocessor and tackle more intricate applications that could benefit society and industry,” Liu said.
Liu, who led this project, has long been at the forefront of quantum technology. Previously, at NTU, Liu spearheaded a significant initiative where his team developed a quantum communication chip that was 1,000 times smaller than existing models. By incorporating quantum key distribution directly into the chip, they significantly enhanced communication security, paving the way for more secure and compact communication technologies.
Zhu is the first author of the research paper detailing the latest breakthrough.