Researchers from the Chinese Academy of Sciences’ Institute of Theoretical Physics (ITP) and Shanghai Jiao Tong University (SJTU) discovered that granular matter (like sand) and some black hole models have similar nonlinear effects. The holographic duality serves as a link between the two. On June 1, the study was published in Science Advances.
Unsolved physical issues can be mapped to tractable higher-dimensional gravitational analogs using holographic duality, and vice versa. The mapping between multiple dimensions is reminiscent of optical holographic projection, hence the name.
Although the holographic duality is rooted in string theory and was developed as part of the search for a consistent theory of quantum gravity, it has since been used to quantum chromodynamics, condensed matter physics, and quantum information.
The concept of holographic duality is used to granular materials, a specific form of athermal, disordered solid. Thermal fluctuations and quantum effects can be ignored because granules have a macroscopic size.
Furthermore, due to the disordered character of granular materials, the classic elasticity theory of ordered crystals is no longer valid (i.e., there is no periodic lattice structure for the spatial distribution of grains). Understanding granular matter’s physical features, such as complicated mechanical responses, is still a theoretical issue.
Granular materials can withstand deformations and maintain structural integrity to some extent. The material, however, fractures when the deformation surpasses a particular threshold, a phenomenon known as yield. Shearing can cause granular system hardening (i.e., an increase in shear modulus), which shows as a nonlinear response to external deformation in some instances.
Based on the holographic duality principle and effective field theory approaches, this work predicts intrinsic correlations between nonlinear elasticity, yielding, and entropy of granular matter. Theoretical predictions are confirmed by computer simulations of granular models.
This study not only broadens the breadth of holographic duality’s applicability but also reveals a possible link between black hole physics and amorphous materials, opening up a new route for the study and comprehension of complex systems.