Power laws in physics have until now always been associated with a scale invariance originating from the absence of a length scale. Recently, an emergent invariance even in the presence of a length scale has been predicted by the newlydeveloped nonlinearLuttingerliquid theory for a onedimensional (1D) quantum fluid at finite energy and momentum, at which the particle’s wavelength provides the length scale. We present experimental evidence for this new type of power law in the spectral function of interacting electrons in a quantum wire using a transportspectroscopy technique. The observed momentum dependence of the power law in the highenergy region matches the theoretical predictions, supporting not only the 1D theory of interacting particles beyond the linear regime but also the existence of a new type of universality that emerges at finite energy and momentum.
 Publication Date:
 NSFPAR ID:
 10153424
 Journal Name:
 Nature Communications
 Volume:
 10
 Issue:
 1
 ISSN:
 20411723
 Publisher:
 Nature Publishing Group
 Sponsoring Org:
 National Science Foundation
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