The previously undetectable quantum excitation—known as 轴向希格斯模式—is a magnetic relative of the mass-defining Higgs Boson particle.
An interdisciplinary team led by 电子游戏软件 physicists has discovered a new particle—or previously undetectable quantum excitation—known as 轴向希格斯模式, a magnetic relative of the mass-defining Higgs Boson particle, 这个团队 报告 在杂志的网络版上 自然.
The detection a decade ago of the long-sought Higgs Boson became central to the understanding of mass. 不像它的母体, 轴向希格斯模式有一个磁矩, and that requires a more complex form of the theory to explain its properties, said 电子游戏软件 Professor of 物理 肯尼斯·伯奇, a lead co-author of the report “Axial Higgs Mode Detected by Quantum Pathway Interference in RTe3.”
Theories that predicted the existence of such a mode have been invoked to explain “dark matter,” the nearly invisible material that makes up much of the universe, 但只有通过重力才能显现出来, 伯奇说.
Whereas Higgs Boson was revealed by experiments in a massive particle collider, 团队专注于RTe3, 或者是稀土三碲化物, a well-studied quantum material that can be examined at room temperature in a “tabletop” experimental format.
肯尼斯·伯奇
“It's not every day you find a new particle sitting on your tabletop," 伯奇说.
RTe3 has properties that mimic the theory that produces 轴向希格斯模式, 伯奇说. But the central challenge in finding Higgs particles in general is their weak coupling to experimental probes, 比如光束, 他说. 类似的, revealing the subtle quantum properties of particles usually requires rather complex experimental setups including enormous 磁铁 and high-powered lasers, while cooling samples to extremely cold temperatures.
The team 报告 that it overcame these challenges through the unique use of the scattering of light and proper choice of quantum simulator, essentially a material mimicking the desired properties for study. 具体地说, the researchers focused on a compound long known to possess a “charge density wave,” namely a state where electrons self organize with a density that is periodic in space, 伯奇说.
The fundamental theory of this wave mimics components of the standard model of particle physics, 他补充说. 然而, 在这种情况下, 电荷密度波很特殊, it emerges far above room temperature and involves modulation of both the charge density and the atomic orbits. This allows for the Higgs Boson associated with this charge density wave to have additional components, 也就是说它可以是轴向的, 也就是说它包含角动量.
In order to reveal the subtle nature of this mode, Burch explained that 这个团队 used light scattering, where a laser is shined on the material and can change color as well as polarization. The change in color results from the light creating the Higgs Boson in the material, while the polarization is sensitive to the symmetry components of the particle.
除了, through proper choice of the incident and outgoing polarization, the particle could be created with different components—such as one absent magnetism, 或者一个向上的分量. Exploiting a fundamental aspect of quantum mechanics, 他们用了一个构型的事实, 这些分量抵消了. 然而, for a different configuration they add.
”这样的, we were able to reveal the hidden magnetic component and prove the discovery of the first axial Higgs mode,伯奇说.
“The detection of the axial Higgs was predicted in high-energy particle physics to explain dark matter,伯奇说. “然而，它从未被观察到. Its appearance in a condensed matter system was completely surprising and heralds the discovery of a new broken symmetry state that had not been predicted. Unlike the extreme conditions typically required to observe new particles, this was done at room temperature in a table top experiment where we achieve quantum control of the mode by just changing the polarization of light.”
伯奇说 the seemingly accessible and straightforward experimental techniques deployed by 这个团队 can be applied to study in other areas.
“Many of these experiments were performed by an undergraduate in my lab,伯奇说. “The approach can be straightforwardly applied to the quantum properties of numerous collective phenomena including modes in superconductors, 磁铁, 铁电体, 电荷密度波. 此外, we bring the study of quantum interference in materials with correlated and/or topological phases to room temperature overcoming the difficulty of extreme experimental conditions."
除了伯奇, 电子游戏软件 co-authors on the report included undergraduate student Grant McNamara, 近期博士电子游戏正规平台生王一平, 以及博士后电子游戏正规平台员Mofazzel Hosen博士. Wang won the Best Dissertation in Magnetism from the American Physical Society, 部分原因是她在这个项目上的工作, 伯奇说.
伯奇说 it was crucial to draw on the broad range of expertise among researchers from BC, 哈佛大学, 普林斯顿大学, 马萨诸塞大学, 阿默斯特, 耶鲁大学, 华盛顿大学, 和中国科学院.
“This shows the power of interdisciplinary efforts in revealing and controlling new phenomena,伯奇说. “不是每天都能看到光学效果的, 化学, 物理理论, 材料科学, 和物理结合在一起."
Ed Hayward | University Communications | June 2022