Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: STM imaging of symmetry-breaking structural distortion in the Bi-based
  cuprate superconductors   A complicating factor in unraveling the theory of high-temperature (high-Tc)
superconductivity is the presence of a "pseudogap" in the density of states,
whose origin has been debated since its discovery [1]. Some believe the
pseudogap is a broken symmetry state distinct from superconductivity [2-4],
while others believe it arises from short-range correlations without symmetry
breaking [5,6]. A number of broken symmetries have been imaged and identified
with the pseudogap state [7,8], but it remains crucial to disentangle any
electronic symmetry breaking from pre-existing structural symmetry of the
crystal. We use scanning tunneling microscopy (STM) to observe an orthorhombic
structural distortion across the cuprate superconducting Bi2Sr2Can-1CunO2n+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 picometer-scale variation in lattice structure, we have
implemented a new algorithm which will serve as a powerful tool in the search
for broken symmetry electronic states in cuprates, as well as in other
materials.

35
The categories of this paper are: mtrl-th
17
The categories of this paper are: q-fin
9
The categories of this paper are: nlin
23
The categories of this paper are: solv-int
34
The categories of this paper are: chem-ph
13
The categories of this paper are: quant-ph
14
The categories of this paper are: math-ph
2
The categories of this paper are: math
20
The categories of this paper are: acc-phys
1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th
26
The categories of this paper are: bayes-an
5
The categories of this paper are: gr-qc
37
The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn