Advancements in Atomic and Quantum Physics: Reading Nuclear Spin with Scanning Tunneling Microscopy
In the realm of advanced technology and modern physics, investigating the atomic and nuclear properties of objects is a scientific priority. One of the essential tools in this field is the Scanning Tunneling Microscope (STM), which can ‘sense’ individual atoms on a surface and produce images with atomic precision. In this context, recent research from Delft University of Technology in the Netherlands stands out, where researchers have succeeded in reading nuclear spin using this advanced tool.
The Scanning Tunneling Microscope and Its Importance
The Scanning Tunneling Microscope is an advanced tool that allows us to examine atomic surfaces with extreme precision. The device consists of a very fine needle capable of sensing individual atoms. In fact, the STM does not directly sense the atomic nucleus itself but detects the electrons surrounding the nucleus. These electrons act like tiny magnets due to a property known as ‘spin,’ which is the quantum equivalent of magnetism.
Scientists, led by Professor Sander Otte, used the STM to sense electron spin for the first time a decade ago. Inspired by this pioneering achievement, the research team wondered if the microscope could also be used to sense nuclear spin.
Challenges in Reading Nuclear Spin
Directly reading nuclear spin using the STM is not possible, as the device is not directly sensitive to nuclear spins. Instead, the team relied on electrons to read nuclear spin indirectly. The general idea had been demonstrated a few years ago using an interaction known as ‘hyperfine interaction’ between electron spin and the nucleus.
The biggest challenge, however, was the speed of measurement. Initial measurements were too slow to capture the movement of nuclear spin over time. Nevertheless, the researchers overcame this obstacle by improving measurement techniques.
Fast Measurements and Real-Time Reading
Researchers Evert Stoll and Jae Won Lee conducted rapid measurements on an atom known to have nuclear spin. By achieving this goal, they were able to observe the signal changing between two distinct levels in real-time on a computer screen.
Stoll announced that these changes indicate the nuclear spin transitioning from one quantum state to another, and vice versa. The researchers determined that it takes about five seconds for the spin to change, which is much longer than other quantum systems available for the STM, such as electron spin in the same atom, which has a lifetime of only about 100 nanoseconds.
Single-Shot Reading and Future Possibilities
Since the researchers were able to measure the state of nuclear spin faster than its transition and without significantly altering the state through measurement, they achieved what is known as ‘single-shot’ reading. This accomplishment opens up exciting experimental possibilities for controlling nuclear spin.
The fundamental progress in reading and controlling surface nuclear spins could, in the long term, contribute to applications such as quantum simulation or quantum sensing at the atomic level. Stoll stated, “The first step in any new experimental frontier is the ability to measure it, and this is what we have achieved for nuclear spins at the atomic level.”
Conclusion
This research represents a significant leap in the field of atomic and quantum physics, as scientists at Delft University of Technology have succeeded in reading nuclear spin using the STM. This achievement enhances the ability to study atomic and quantum systems with unprecedented detail, opening new horizons in scientific research and future technological applications. The potential to control nuclear spin using such advanced techniques could have far-reaching impacts in various fields of technology and science.