Solids, liquids, and gases under high pressure - Dr. Ho-Kwang Mao

MARCH 20, 2018

Pressure has long been recognized as a fundamental thermodynamic variable. It drastically alters physical and chemical properties of materials. A review on Reviews of Modern Physics from HPSTAR researchers led by Dr. Ho-Kwang, provides an in-depth review of how pressure drastically change our world and the key developments that have led to surprising high-pressure physics and chemistry and created novel materials along with the current status and future perspectives of multidisciplinary advancement in high-pressure chemistry, geoscience, astrophysics, and materials applications.

In this paper, the authors particularly focus on describing the principles and methodology used to reach ultrahigh static pressure: the in situ probes, the physical phenomena to be investigated, the long-pursued goals, the surprising discoveries, and the vast potential opportunities.

“High Pressure should be viewed as an unexplored dimension. Consequently, our “ordinary” pressure world should be regarded as a special condition in the pressure dimension”, said Dr. Mao. “The science and technology that have been developed for this “special condition” can now be used to explore the unknown physics in the vast overall pressure dimension and new knowledge gained at each segment of pressure advances the generalized rule of physics”.

First, the paper reviewed the developments of static high pressure—diamond anvil cell related techniques and multiple probes integrated with diamond anvil cell over the past decades.

The following exciting examples achieved under static pressure are discussed in this review: the quest for metallic hydrogen, the record-breaking superconducting temperature of 203 K in HnS, the complication of “free-electron gas” alkali metals, the magnetic collapse in 3d transition elements, the pressure-induced superconductivity from topological insulators, the novel stoichiometry in simple compounds, the interaction of nanoscience, the accomplishment of 750 GPa pressure, etc.

The detailed overview shows a hopeful outlook for the future multidisciplinary advancements in high-pressure chemistry, geoscience, astrophysics, and materials applications. The authors also underline the importance of synergetic advances to allow greater progress in fundamental physics.

Caption: Configuration of a pair of opposed diamond anvils squeezing the sample chamber to generate ultrahigh pressure. The sample chamber is a hole in the gasket thatcontains the sample and a pressure medium.

The other authors are Drs. Bin Li, Xiaojia Chen, Yang Ding and Lin Wang of HPSTAR.

北京高压科学研究中心主任，毛河光院士应邀在《现代物理评论》（Review of Modern Physics）发表了一篇关于物质在高压下的综述文章。该论文首先回顾了静高压技术的发展，讨论了静高压下观测到的有趣的物理，化学等现象。提出在压力这个维度下，我们正面临着一个新的物质世界：绝缘体-超导，晶体-非晶，以及离子键-共价键的转化等等。可以说压力开辟了一个新的凝聚态世界。 同时这篇综述展望了高压在各学科：化学，地学，天气物理，及材料等交叉学科的未来发展，提出高压的进步依赖于各学科共同进步。