Chasing the Hofstadter Butterfly
Chasing the Hofstadter Butterfly
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追逐霍夫施塔特蝴蝶
DOI:
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发表时间:
2014
期刊:
影响因子:
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通讯作者:
I. Satija
中科院分区:
文献类型:
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作者:
I. Satija
We revisit the problem of self-similar properties of the Hofstadter butterfly spectrum, focusing on spectral as well as topological characteristics. In our studies involving all values of magnetic flux, we single out the most dominant hierarchy in the spectrum, which is found to be associated with an irrational number ζ = 2 − √ 3. Characterizing an intrinsic frustration at smallest energy scale, this hidden quasicrystal encodes hierarchical set of topological quantum numbers associated with Hall conductivity and their scaling properties. This topological hierarchy is also mapped to an integral Apollonian gasket ( also known as Curvilinear Sierpinski gasket ) that asymptotically exhibits D3 symmetry, revealing a hidden symmetry of the butterfly as the energy and the magnetic flux intervals shrink to zero. With a periodic drive that induces phase transitions in the system, the fine structure of the butterfly is shown to be amplified making states with large topological invariants accessible experimentally.