In a recent groundbreaking study highlighted in Science Advances, a collaborative team led by Associate Professor Nobuhiro Yanai at Kyushu University’s Faculty of Engineering achieved a significant leap in room temperature quantum coherence. Quantum coherence, denoting a quantum system’s ability to maintain a stable state despite external disturbances, was realized through the innovative incorporation of a chromophore—a light-absorbing dye molecule—into a metal-organic framework (MOF). This nanoporous crystalline material, composed of metal ions and organic ligands, has far-reaching implications for the realms of quantum computing and sensing technologies.
Unlocking the Secrets of Qubits
The study explores the unique properties of qubits, quantum counterparts of classical bits capable of existing in a superposition of 0 and 1. One approach involves leveraging intrinsic spin, a quantum property related to a particle’s magnetic moment. Electrons, with spin states of up and down, can be entangled, allowing the state of one qubit to be inferred from another.
Challenges in Quantum Sensing Technology
Quantum sensing technology, promising higher resolution and sensitivity, faces challenges in using a nanoporous MOF to entangle four electrons and make them responsive to external molecules. Chromophores, crucial for exciting electrons at room temperature, presented hurdles in achieving quantum coherence without the need for extremely low temperatures.
Innovative Solution: Pentacene-based Chromophore and UiO-type MOF
To overcome these challenges, researchers introduced a pentacene-based chromophore into a UiO-type MOF. Yanai notes, “The unique MOF system in this study densely accumulates chromophores, and the nanopores allow controlled rotation.” This structure facilitated electron transition from the triplet to quintet state, maintaining quantum coherence at room temperature. Using microwave pulses to photoexcite electrons, the team observed room-temperature quantum coherence for over 100 nanoseconds, marking a groundbreaking achievement in entangled quintets.
Future Prospects and Quantum Efficiency
While the coherence duration is currently limited to nanoseconds, the study lays the foundation for designing materials capable of generating multiple qubits at room temperatures. Yanai envisions enhanced efficiency in generating quintet multiexciton state qubits through the discovery of guest molecules inducing suppressed motions and the development of suitable MOF structures. This breakthrough opens doors to potential applications in room-temperature molecular quantum computing and quantum sensing for various target compounds, utilizing multiple quantum gate controls.
“As an observer intrigued by advancements in quantum computing, I am thrilled by the revolutionary strides unveiled in this study. The attainment of room-temperature quantum coherence, employing cutting-edge methods such as integrating chromophores into metal-organic frameworks, not only expands the horizons of scientific inquiry but also lays the foundation for transformative progress in quantum computing and sensing technologies. This breakthrough underscores a dedication to pioneering advancements, propelling the quantum computing landscape forward. It is a testament to the commitment to unlocking the potential of quantum coherence, shaping a future where quantum computing is accessible and highly efficient, ushering in unparalleled possibilities and innovation.” – Mark Kelly, founder of Quantum Computing Ireland