We theoretically propose an experimentally viable scheme to use an impurity atom in a dipolar Bose-Einstein condensate (BEC), in order to probe analogue low-energy Lorentz violation from the modified dispersion at high energies as suggested by quantum theories of gravity. We show that the density fluctuations in the dipolar BEC possess a Lorentz-violating Bogoliubov spectrum $ω_\mathbf{k}=c_0|\mathbf{k}|f(c_0|\mathbf{k}|/M_\star)$, with recovery of approximate Lorentz invariance (LI) at energy scales much below $M_\star$. When $f$ is adjusted to dip below unity somewhere, the impurity, analogously dipole coupled to the density fluctuations, experiences analogue drastic Lorentz violation at arbitrarily low energies, reproducing the same responds of Unruh-DeWitt detector to Lorentz-violating quantum fields. Being a fundamentally quantum mechanical device, our quantum fluid platform provides an experimentally realizable test field to verify whether the effective low energy theory can reveal unexpected imprints of the theory's high energy structure, in quantum field theory.
Engineering and Probing a One-Dimensional Dipolar Spin Ensemble in Diamond
University of California, Santa Barbara（加州大学圣塔芭芭拉分校）；California Institute of Technology（加州理工学院）；Stanford University（斯坦福大学）；Harvard University（哈佛大学）；Boston University（波士顿大学）；Max-Planck-Institut für Physik Komplexer Systeme（马克斯·普朗克复杂系统物理研究所）
Probing Lorentz-invariance-violation with quantum coherence of Unruh-DeWitt detector
School of Physics, Hangzhou Normal University（杭州师范大学物理学院）；Department of physics and electrical engineering, Liupanshui Normal University（六盘水师范学院物理与电气工程系）
