• Published in ACS Physical Chemistry Au, introducing an SVD quantum algorithm for open quantum system approaches. • Applied to key quantum biological systems, including excitonic energy transport in the photosynthetic FMO complex and the avian compass radical pair mechanism. • Captures both short- and long-time dynamics accurately... Demonstrating potential as a future tool for simulating complex in vivo nonunitary quantum dynamics. [Quantum Biology Society] A new algorithmic approach capable of modeling and predicting complex nonunitary quantum dynamics inside living organisms using quantum computers has been successfully validated. A research paper titled "Singular Value Decomposition Quantum Algorithm for Quantum Biology" was published in the international journal ACS Physical Chemistry Au. A joint research team led by Professor Kade Head-Marsden from Washington University in St. Louis presented a groundbreaking mathematical framework to solve modeling challenges in quantum biology. ■ Breaking Through Simulation Limits with 'Open Quantum Systems' There has been growing academic interest in algorithms for predicting nonunitary quantum dynamics using current quantum computers. In the field of quantum biology, it is virtually impossible to treat large and complex biological systems entirely as quantum states. However, an open quantum systems approach, which considers continuous interaction with the environment and dissipation, can make these quantum algorithms highly useful. Accordingly, the researchers introduced the Singular Value Decomposition (SVD) quantum algorithm, which helps implement complex nonunitary operators on quantum circuits, and applied it to two major challenges in quantum biology. ■ Secrets of Photosynthesis and Avian Compass Captured by SVD Algorithm The systems the research team applied the SVD algorithm to are: 1) excitonic energy transport through the Fenna-Matthews-Olson (FMO) complex in the photosynthetic process of green sulfur bacteria, and 2) the radical pair mechanism (RPM) of avian navigation, where migratory birds find their way by sensing the Earth's magnetic field. The researchers implemented and analyzed this using the IBM QASM quantum simulator. The results confirmed that the SVD algorithm very accurately captures and reproduces the environment-driven dynamical processes appearing in both biological systems across both short- and long-time quantum dynamics, regardless of the time duration. This study holds great significance in that it demonstrated the potential of the SVD quantum algorithm to become a powerful and effective tool for simulating complex in vivo quantum mechanics as quantum computing advances, even though such complex biological systems face physical limitations for perfect implementation at the current level of noisy intermediate-scale quantum (NISQ) hardware. Experts anticipate that this algorithm will accelerate quantum biology research and play a key role in designing biomimetic quantum technologies and new drug discovery platforms.
• Published in ACS Physical Chemistry Au, introducing an SVD quantum algorithm for open quantum system approaches. • Applied to key quantum biological systems, including excitonic energy transport in the photosynthetic FMO complex and the avian compass radical pair mechanism. • Captures both short- and long-time dynamics accurately... Demonstrating potential as a future tool for simulating complex in vivo nonunitary quantum dynamics. [Quantum Biology Society] A new algorithmic approach capable of modeling and predicting complex nonunitary quantum dynamics inside living organisms using quantum computers has been successfully validated. A research paper titled "Singular Value Decomposition Quantum Algorithm for Quantum Biology" was published in the international journal ACS Physical Chemistry Au. A joint research team led by Professor Kade Head-Marsden from Washington University in St. Louis presented a groundbreaking mathematical framework to solve modeling challenges in quantum biology. ■ Breaking Through Simulation Limits with 'Open Quantum Systems' There has been growing academic interest in algorithms for predicting nonunitary quantum dynamics using current quantum computers. In the field of quantum biology, it is virtually impossible to treat large and complex biological systems entirely as quantum states. However, an open quantum systems approach, which considers continuous interaction with the environment and dissipation, can make these quantum algorithms highly useful. Accordingly, the researchers introduced the Singular Value Decomposition (SVD) quantum algorithm, which helps implement complex nonunitary operators on quantum circuits, and applied it to two major challenges in quantum biology. ■ Secrets of Photosynthesis and Avian Compass Captured by SVD Algorithm The systems the research team applied the SVD algorithm to are: 1) excitonic energy transport through the Fenna-Matthews-Olson (FMO) complex in the photosynthetic process of green sulfur bacteria, and 2) the radical pair mechanism (RPM) of avian navigation, where migratory birds find their way by sensing the Earth's magnetic field. The researchers implemented and analyzed this using the IBM QASM quantum simulator. The results confirmed that the SVD algorithm very accurately captures and reproduces the environment-driven dynamical processes appearing in both biological systems across both short- and long-time quantum dynamics, regardless of the time duration. This study holds great significance in that it demonstrated the potential of the SVD quantum algorithm to become a powerful and effective tool for simulating complex in vivo quantum mechanics as quantum computing advances, even though such complex biological systems face physical limitations for perfect implementation at the current level of noisy intermediate-scale quantum (NISQ) hardware. Experts anticipate that this algorithm will accelerate quantum biology research and play a key role in designing biomimetic quantum technologies and new drug discovery platforms.
There has been a recent interest in quantum algorithms for the modeling and prediction of nonunitary quantum dynamics using current quantum computers. The field of quantum biology is one area where these algorithms could prove to be useful as biological systems are generally intractable to treat in their complete form but amenable to an open quantum systems approach. Here, we present the application of a recently developed singular value decomposition (SVD) algorithm to two systems in quantum biology: excitonic energy transport through the Fenna-Matthews-Olson complex and the radical pair mechanism for avian navigation. We demonstrate that the SVD algorithm is capable of capturing accurate short- and long-time dynamics for these systems through implementation on a quantum simulator and conclude that while the implementation of this algorithm is beyond the reach of current quantum computers, it has the potential to be an effective tool for the future study of systems relevant to quantum biology.
Many living organisms can exploit quantum mechanical effects to gain distinct biological advantages. In plants, photosynthesis uses quantum coherence to achieve near 100% efficiency in energy transfer. With advances in experimental techniques, two-dimensional electronic spectroscopy can reveal dynamic processes such as coherence and coupling within a system, and it plays an important role in studying energy transfer in photosynthesis. On the theory side, methods such as the generalized Bloch-Redfield theory and the hierarchical equations of motion are used to model photosynthetic systems. Quantum simulation, as a high-efficiency and low-complexity approach, has also made progress across various platforms in the study of photosynthesis. In recent years, a series of studies has introduced quantum coherence into artificial systems to enhance energy transfer efficiency, laying the groundwork for the design of coherent devices with efficient energy transport. Birds can use the weak geomagnetic field and spin-dependent chemical reactions to detect direction. Theoretical frameworks for animal navigation include magnetite-based mechanisms, magnetoreceptor genes, and the radical-pair mechanism. Quantum simulations of navigation have also advanced on multiple platforms. Inspired by animal navigation, diverse quantum effects have been applied to improve sensing and to support navigation tasks. This paper presents a comprehensive review of progress on quantum coherence in photosynthesis and avian navigation, along with related theoretical methods, quantum simulation approaches, and research on quantum coherent devices.
• Published in AIP Publishing's APL Quantum, fully applying digital quantum simulation (DQS) to spin biology. • Successfully implemented the quantum spin dynamics of the radical pair mechanism utilizing the 'Trotterization' technique. • Analyzed the noise limits of actual quantum hardware and demonstrated the potential of utilizing quantum computing for the future development of new drugs targeting complex biomolecules. [Quantum Biology Society] In the emerging field of quantum biology, simulating spin-chemistry systems with actual biological complexity has posed computational limitations that are difficult to overcome with conventional classical computers. This is because as the number of elements constituting the spin system increases, the dimension of the Hilbert space required for computation grows exponentially. Recently, a study simulating biological phenomena using an actual digital quantum computer was published to resolve this problem, drawing the attention of the academic community. A paper titled "Simulating spin biology using a digital quantum computer: Prospects on a near-term quantum hardware emulator" was published on August 19 in APL Quantum, a journal of AIP Publishing. This research was led by a multinational joint research team including Pedro H. Alvarez and Clarice D. Aiello. ■ Mapping the Radical Pair Mechanism via Trotterization The radical pair mechanism (RPM), represented by the magnetic field sensing (magnetoreception) ability of migratory birds, centers on the quantum entanglement and coherence phenomena of electron spins in vivo. The research team introduced the Trotterization technique to directly apply gate-based digital quantum simulation (DQS) to biological systems. Through this technique, they successfully mapped the coherent spin dynamics of radical pairs onto quantum circuits. In ideal, noise-free quantum circuit simulations, they obtained accurate spin dynamics results consistent with the conventional classical Haberkorn master equation approach using only about 15 Trotter steps. ■ Analysis of Quantum Hardware Noise Limits and Future Prospects Furthermore, going beyond ideal environments, the research team conducted an in-depth analysis of the impact of realistic error models on simulations using a near-term (NISQ) quantum hardware emulator that mimics the noise profile of an IBM quantum device (e.g., ibmq_jakarta). The analysis revealed that realistic limitations were observed due to the constrained performance and noise (such as phase damping and amplitude damping) of current quantum hardware, including a shift in singlet yield and a decreased ability to sense magnetic field anisotropy. However, the researchers showed that by fitting an analytical model to the measured noisy data, the overall dynamical shape depending on the magnetic field angle could be successfully derived. In addition, they presented a practical upper limit for the number of Trotter steps that can be directly run on quantum devices if error mitigation techniques are introduced in the future. Unlike conventional classical computing methods that face exponential limits, the DQS approach possesses the potential to efficiently model biological spin systems simply through linear resource scaling by adding qubits. This study is evaluated as a groundbreaking first step demonstrating that digital quantum simulation can be utilized as an innovative tool for new drug development targeting complex biomolecules and ultra-precise biosensing modeling by directly calculating the entanglement and coherence of biological phenomena.
• A Perspective paper published in PNAS presents the scope and future research directions of quantum biology. • Focuses on quantum coherence and synchronization at macroscopic scales, rather than simply being a collection of unexplained phenomena. • Proposes three core open questions: the development of quantum probes, quantum-like classical systems, and the macroscopic amplification of microscopic quantum effects. [Quantum Biology Society] Generally, the "warm, wet, and noisy" environment that makes up living organisms is considered the most hostile condition for true quantum effects like entanglement or coherence to exist. However, elucidating how living organisms overcome these paradoxical limitations and utilize unique quantum wave-like properties for functional advantages is the very core of "quantum biology." Recently, a Perspective paper titled "What is quantum biology?" was published in the Proceedings of the National Academy of Sciences (PNAS), drawing the attention of the academic community. A research team including Gregory D. Scholes and Graham R. Fleming clearly declared that quantum biology is not simply a "grab bag of biological phenomena that cannot be fully explained quantitatively by current science." ■ 'Coherence' and 'Synchronization' Governing Life Phenomena The paper reviews existing representative studies, such as exciton spreading in photosynthesis and avian navigation (magnetic field sensing), focusing on the "coherence" and "resonance" phenomena occurring in vivo. According to the researchers, the evolutionary process finely tuned the local protein environments of chromophores to closely match electronic and vibrational energy gaps. This optimization of frequency resonance is strong evidence that living organisms actively utilize quantum mechanical entanglement and wave properties to gain macroscopic physiological advantages. Furthermore, they explained that noise does not merely act as a destructive factor that collapses quantum states; rather, it can play a beneficial role in amplifying minute quantum signals and assisting transport through "stochastic resonance" or "quantum ratchet" mechanisms. ■ 3 Core Open Questions for the Future of Quantum Biology The researchers proposed three core open questions that must be resolved to firmly establish quantum biology as an independent discipline and focus future research agendas. 1. Development of quantum probes: Measurement technologies called "quantum probes" are needed to clearly and sharply reveal the quantum functions hidden within complex biological systems. 2. Identification of quantum-like systems: It must be determined whether classical biological machineries have the potential to exhibit useful properties as if possessing a "quantum advantage" simply by mimicking quantum systems. 3. Amplification to the macroscopic scale: We must understand the missing link of how microscopic-scale quantum mechanical mechanisms are amplified to the biological scale, providing the foundation for new macroscopic functions. This paper clearly redefined the scope of quantum biology into categories including: ▲ interactions with fields such as light, magnetic, and electric fields; ▲ various forms of coherence phenomena; ▲ microscopic quantum dynamical systems including spin and proton tunneling; and ▲ complex systems that mimic quantum phenomena through networks. Experts anticipate that this study will serve as an important compass for future quantum biology research, going beyond merely confirming the physical laws of the microscopic world to asking how living organisms control and optimize quantum phenomena in macroscopic environments.
We humans always want to believe that we can overpower nature. However, the reality is that nature outperforms humans in many aspects. Animals' abilities to navigate/orient and photosynthesis are two excellent examples in these aspects. However, the mechanisms underlying them are still unknown. For decades, scientists and researchers have made a lot of efforts to reveal these mysteries in nature. Recently, quantum coherence and entanglement are believed to play a crucial role in such biological systems–avian compass and photosynthesis. Thus, nature might know more tricks to utilize quantum mechanics than humans. Studies on the mechanisms underlying avian compass and photosynthesis are highly able to improve or inspire new technologies in detection of weak magnetic fields and solar cells. In this thesis, the effect of quantum coherence and entanglement in these systems is studied. Based on the studied systems, this thesis falls into two parts: avian compass–radical pair mechanism and photosynthesis–enhancing photocell efficiency via coherence. The radical pair mechanism used to explain the avian compass is studied in the first part. It is demonstrated that Cryptochrome is a suitable candidate of the primary magnetoreceptor, located in birds' eyes. Also, the product yields due to the radical pair reactions are able to act as the direction signal for birds. The long-lived quantum entanglement has presented between the radical pairs. In photosynthesis, quantum coherence has been demonstrated to play an essential role in high energy conversion efficiency. Studies have revealed that the quantum coherence can break the detailed balance, the key factor limiting the efficiency in artificial solar cells. By mimicking photosynthetic complexes, a designed solar cell taking advantage of coherent donors caused by dipole-dipole interactions is able to achieve a higher energy conversion efficiency than the famous Shockley-Queisser limit. Again, more and more evidence has shown that quantum mechanics is able to play a crucial role in biological systems. Quantum coherence and entanglement, as main signatures of quantum mechanics, can be used to explain many astonishing phenomena in nature, such as avian magnetoreception and photosynthesis. Learning from nature can accelerate developments of new technologies.
Quantum biology is now taken rather seriously. Photosynthesis and avian navigation are two key applications of quantum biology. The basic problem in both cases is posed by the fact that the magnetic interaction energy in Earth's magnetic field is roughly million times smaller than thermal energy. The so called radical-pair mechanism (RPM) was proposed already in the 60's as a possible solution to the problem posed by anomalously large effect in EPR and NMR experiments. According to RPM, a radical pair is accompanied by electron pair, which is in a superposition of spin triplet and singlet states and behaves as quantum coherent system for a time sufficiently long to induce chemical effects. The hyperfine interaction of the members of the electron pair with the nuclei of radicals would amplify the effect. The neutralization of radical pair puts an end to the coherence interaction period. The proposal is that RPM gives rise to chemical compass making possible avian navigation. There is however a problem. RPM has been observed in laboratory only for magnetic fields in the range 1 mT-10 T. Earth's magnetic field is only 2 per cent of the lower bound so that it is quite possible that RPM is not at work. This opens up the door for new quantum physics proposed by TGD based model of quantum biology. In this approach magnetic body acts as as intentional agent using biological body as a sensory receptor and motor instrument. Macroscopic quantum coherence is made possible by dark matter realized as a hierarchy of heff = n x h phases. In this article RMP is summarized and compared with the TGD based vision. Also the possible connection between avian navigation and circadian clock suggested by the fact that both involve photoreceptor known as cryptocrome and a possible connection with gravitaxis are considered in TGD framework.