A new matter phase, dubbed the “chiral bose-liquid state,” has been revealed by physicists, offering robust features such as invariant electron spin and far-reaching entanglement. Investigating kinetic frustration in quantum systems led to this finding, which requires high magnetic fields for examination. This discovery enriches our comprehension of the physical realm and may offer practical use in resilient digital data encoding.
For Experimental Physicists, Unraveling Quantum Mysteries Yields Essential Revelation
UMass Amherst professor confirms the existence of a new matter phase, the “chiral bose-liquid state.”
In a recent article published in Nature, a physicist team, including Tigran Sedrakyan, an assistant professor at the University of Massachusetts, reported the discovery of a new matter phase, the “chiral bose-liquid state.” This revelation ushers in a new direction in the timeless quest to comprehend the essence of the physical universe.
Ordinary circumstances allow matter to exist as a solid, liquid, or gas. However, venturing into extreme conditions—nearing absolute zero temperatures or dealing with entities smaller than an atom fraction or with extremely low energy states—transforms the perception of reality. Sedrakyan notes, “Out there on these fringes, you encounter quantum states of matter, far more extraordinary than the three classical states we experience daily.”
Sedrakyan has dedicated years to examining these exotic quantum states, fascinated by potential instances of “band degeneracy,” “moat bands,” or “kinetic frustration” in quantum matter featuring strong interactions.
Rendering of the moat band that incites particles and triggers the chiral bose-liquid state. Credit: Tigran Sedrakyan
In most scenarios, particles in a system collide, inducing predictable outcomes, akin to billiard balls reacting in a foreseeable pattern after impact. This suggests that particles and effects are correlated. Yet, a frustrated quantum system generates infinite possibilities from particle interaction, potentially leading to unique quantum states.
Sedrakyan, along with his team, have developed a frustration device—a bilayer semiconducting apparatus. The top layer is teeming with electrons with free mobility, while the bottom layer houses “holes,” or potential spots for wandering electrons. The two layers are then brought exceedingly close— to an interatomic distance.
Under normal circumstances, an equal number of electrons in the top layer and holes in the bottom layer would induce predictable, correlated behavior among particles. However, Sedrakyan and his team designed an imbalance between the number of electrons and holes in the bottom layer, similar to a game of musical chairs, provoking the electrons. Instead of having a single option for each electron, multiple options now exist, leading to a state of “frustration.”
The resultant frustration initiates the novel chiral edge state, with several remarkable attributes. For instance, if quantum matter in a chiral state is cooled to absolute zero, the electrons settle into a predictable pattern. The arising charge-neutral particles in this state will all spin either clockwise or counterclockwise. This spin remains constant, regardless of collision with other particles or the introduction of a magnetic field, offering robustness suitable for fault-tolerant digital data encoding.
Intriguingly, if an external particle collides with a particle in the chiral edge state, it doesn’t just affect that single particle. Instead, using the billiard ball analogy, if the pool balls were in a chiral bose-liquid state, all of them would respond identically when one is struck. This effect originates from the extensive entanglement present in this quantum system.
Observing the chiral bose-liquid state is challenging, which is why it remained undiscovered for so long. To accomplish this, a team of scientists, including theoretical physicists Rui Wang and Baigeng Wang of Nanjing University, and experimental physicists Lingjie Du (Nanjing University) and Rui-Rui Du (Peking University) designed a theory and an experiment requiring an extremely strong magnetic field to measure the racing electrons’ movements.
Lingjie Du explains, “At the semiconductor bilayer’s edge, electrons and holes move at identical velocities. This induces a helix-like transport, further regulated by external magnetic fields as the electron and hole channels gradually separate under increased fields.” The magneto-transport experiments thus successfully uncovered the first evidence of the chiral bose-liquid, also referred to as the “excitonic topological order” in the published paper.
Reference: “Excitonic topological order in imbalanced electron–hole bilayers” by Rui Wang, Tigran A. Sedrakyan, Baigeng Wang, Lingjie Du and Rui-Rui Du, 14 June 2023, Nature.
Support for this research came from the National Key R&D Program of China, the National Natural Science Foundation of China, the Program for Innovative Talents and Entrepreneurs in Jiangsu, the Xiaomi Foundation, the Chinese Academy of Sciences, and the National Science Foundation.
Frequently Asked Questions (FAQs) about Chiral bose-liquid state
What is the newly discovered phase of matter?
The newly discovered phase of matter is called the “chiral bose-liquid state.” It exhibits robust properties such as invariant electron spin and long-range entanglement. The discovery of this state was made possible through the exploration of kinetic frustration in quantum systems.
Who were the key contributors to this discovery?
The discovery was made by a team of physicists, including Tigran Sedrakyan, an assistant professor at the University of Massachusetts, along with theoretical physicists Rui Wang and Baigeng Wang of Nanjing University, and experimental physicists Lingjie Du (Nanjing University) and Rui-Rui Du (Peking University).
What are the possible applications of the chiral bose-liquid state?
The chiral bose-liquid state’s robust properties can be applied in the field of digital data encoding in a fault-tolerant manner. This could potentially revolutionize how data is stored and processed.
What was the method used to observe the chiral bose-liquid state?
The chiral bose-liquid state was observed using an experimental design involving a bilayer semiconducting device and an extremely strong magnetic field. The researchers engineered a local imbalance of electrons and “holes” in the layers of the device to induce the chiral state.
Why is this discovery considered groundbreaking?
This discovery represents a significant advancement in quantum physics, as it reveals a new phase of matter beyond the conventional solid, liquid, and gas states. It also provides insights into the effects of quantum frustration, and its application could revolutionize digital data encoding.
More about Chiral bose-liquid state
- Excitonic topological order in imbalanced electron–hole bilayers
- Understanding Quantum Frustration
- Introductory Quantum Mechanics
- Basics of Quantum Entanglement