When everything around us evolves, our thoughts sometimes also get a boost. Can we ‘see’ thoughts without opening the brain? Thanks to quantum physics, Scientists are getting closer to making that possible.
Quantum physics is a field of science dedicated to examining how matter and energy behave at tiny scales, such as those of atoms and subatomic particles. It challenges the conventional understanding by demonstrating that particles can occupy multiple states simultaneously (known as superposition), affect one another instantaneously across distances (a phenomenon called entanglement), and display characteristics of both waves and particles. During the early 1900s, pioneering scientists like Planck, Einstein, Bohr, and Schrödinger shaped a theory that revolutionised our understanding of reality and laid the foundation for semiconductors, lasers, and quantum computers.
As quantum physics has improved our understanding of the physical world, the discipline of biology has also experienced major transformations. It has transitioned from merely observational natural history to a more rigorous experimental approach. While physicists have deciphered the complexities of atomic and subatomic behaviour, biologists have made revolutionary discoveries that have laid the groundwork for contemporary genetics, microbiology, and molecular biology.
What is Quantum Sensing?
Quantum sensing is a sophisticated technology that utilises quantum mechanics concepts, including superposition, entanglement, and coherence, to gauge physical quantities with remarkable precision. In contrast to classical sensors, quantum sensors can detect minuscule variations in magnetic and electric fields, temperature and pressure, acceleration and rotation, time, and gravitational forces.
Quantum sensors make use of quantum systems like atoms, ions, and photons that respond to external factors such as magnetic fields. These sensors can detect changes with exceptional sensitivity thanks to their quantum properties. Key quantum effects include superposition, allowing the sensor to operate in multiple states simultaneously; entanglement, which improves accuracy by connecting particles over distances; and quantum coherence, which helps maintain stable quantum states for more precise measurements.
This technology is used across various fields such as healthcare, navigation, defence, environmental research, and theoretical physics. In medicine, one key use is for brain imaging and diagnostic purposes.
Brain imaging involves a range of methods to visualise the anatomy and activity of the brain. These tools help scientists and clinicians understand how the brain works, identify neurological conditions, and monitor the impact of treatments. Brain imaging can be categorised into two main types: structural imaging, which provides detailed representations of anatomical structures, and functional imaging, which illustrates the activity and functions of the brain.
What is Quantum sensing in Brain imaging?
Quantum sensing, especially with optically pumped magnetometers (OPMs), transforms brain imaging by providing improved sensitivity and spatial resolution relative to conventional techniques such as fMRI. While functional magnetic resonance imaging (fMRI) is commonly used for brain imaging, it faces limitations in how precisely it captures both the location and timing of brain activity.
,p>Quantum sensors enable the recording of brain activity from the skull's surface with a spatial and temporal resolution level that was previously impossible. This technology could facilitate the control of intricate robotic movements or reconstruct imagined speech from neuromagnetic brain signals.
The fundamental concept of quantum sensors utilised in brain imaging is their capacity to identify very faint magnetic fields produced by neural activity, which classical sensors find challenging to measure accurately.
Neurons transmit data through electrical signals that create small magnetic fields. Quantum sensors can accurately detect these fields, especially those employing Superconducting Quantum Interference Devices (SQUIDs) or optically pumped magnetometers (OPMs). The operation of these sensors relies on several principles: certain particles, like electrons and atomic nuclei, possess a property called spin, which acts like a tiny magnet. When these particles encounter external magnetic fields, their spin states experience measurable alterations. Furthermore, superposition and entanglement quantum features allow these sensors to detect tiny fluctuations in magnetic fields with great precision and minimal interference. SQUIDs utilise superconducting loops to identify changes in magnetic flux and are extensively employed in magnetoencephalography (MEG) to visualise brain activity due to their high sensitivity. In contrast, OPMs use laser light to manipulate and read the spin states of atoms, like rubidium or caesium, making them compact, wearable, and not needing cryogenic cooling, unlike their SQUID counterparts.
Researchers are working on quantum sensors incorporating diamonds, OPMs, and SQUIDs. These diamond magnetometers, in theory, could provide even finer resolution. Quantum diamond sensors are cutting-edge tools that utilise the unique quantum features of defects in synthetic diamonds, particularly nitrogen-vacancy (NV) centres, to detect tiny magnetic, electric, and thermal signals with outstanding accuracy. They provide an impressive blend of room-temperature functionality, nanoscale precision, and non-invasive detection, which makes them perfect for advanced biomedical and technological uses.
Why does this Matter?
Quantum sensors, especially those that use diamond NV centres, SQUIDs, and optically pumped magnetometers, are significantly advancing our comprehension and interaction with the brain. They allow scientists to visualise neural activity in real-time with outstanding spatial and temporal precision, making it possible to detect magnetic fields generated by individual neurons, which conventional tools like EEG or fMRI cannot accomplish.
This technology allows for the non-invasive exploration of deep brain regions, offering new insights into the development of thoughts, emotions, and disorders within the brain. Furthermore, quantum sensors revolutionise brain-computer interfaces (BCIs) by providing non-invasive, high-resolution detection of brain signals, improving control over prosthetics, exoskeletons, and communication devices. They enable real-time interpretation of brain activity, allowing users to interact with machines solely through their thoughts while minimising the need for risky surgical implants, thereby increasing the safety and accessibility of BCIs, especially for individuals with paralysis, amputations, or neurodegenerative conditions.
In addition, quantum sensors could be vital for the early detection of neurological diseases like Parkinson’s and Alzheimer’s by identifying slight changes in brain magnetic fields associated with initial stages and tracking neural deterioration before symptoms appear. This advancement may enable the creation of cost-effective, wearable devices for continuous brain monitoring, leading to earlier diagnosis, better treatment results, and more personalised care approaches.
As quantum sensor technology becomes more compact, affordable, and wearable, we are moving toward a future where brain imaging is as simple as wearing a headset. Brain-Computer Interfaces (BCIs) will become mainstream tools for communication and mobility, and neurological health will be monitored proactively rather than reactively.
Could quantum sensors be used in future to decode dreams? Science may be on its way to finding out.