Zeljkovic, IlijaMain, Elizabeth J.Williams, Tess LawannaBoyer, M. C.Chatterjee, KamaleshWise, W. D.Yin, YiZech, MartinPivonka, Adam EdwardKondo, TakeshiTakeuchi, T.Ikuta, HiroshiWen, JinshengXu, ZhijunGu, G. D.Hoffman, Jenny2012-05-182012Zeljkovic, Illija, Elizabeth J. Main, Tess L. Williams, M. C. Boyer, Kamalesh Chatterjee, W. D. Wise, Yi Yin, et al. Forthcoming. Scanning tunnelling microscopy imaging of symmetry-breaking structural distortion in the bismuth-based cuprate superconductors. Nature Materials.1476-11221476-4660http://nrs.harvard.edu/urn-3:HUL.InstRepos:8784321A complicating factor in unravelling the theory of high-temperature (high-\(T_c\)) superconductivity is the presence of a ‘pseudogap’ in the density of states, the origin of which has been debated since its discovery. Some believe the pseudogap is a broken symmetry state distinct from superconductivity whereas others believe it arises from short-range correlations without symmetry breaking. A number of broken symmetries have been imaged and identified with the pseudogap state, but it remains crucial to disentangle any electronic symmetry breaking from the pre-existing structural symmetry of the crystal. We use scanning tunnelling microscopy to observe an orthorhombic structural distortion across the cuprate superconducting \(Bi_{2}Sr_{2}Ca_{n−1}Cu_{n}O_{2n+4+x}\) (BSCCO) family tree, which breaks two-dimensional inversion symmetry in the surface BiO layer. Although this inversion-symmetry-breaking structure can impact electronic measurements, we show from its insensitivity to temperature, magnetic field and doping, that it cannot be the long-sought pseudogap state. To detect this picometre-scale variation in lattice structure, we have implemented a new algorithm that will serve as a powerful tool in the search for broken symmetry electronic states in cuprates, as well as in other materials.en-USsuperconductivityJournal Article2012-11-0710.1038/nmat3315