Battling quantum decoherence, one flat band at a time

Researchers establish a novel way to strengthen electron correlations by controlling flat band electronic structures in Transition Metal Dichalcogenide.

By Lubaba Hoque, Transformative Quantum Technologies

Quantum decoherence is often a challenge that quantum scientists seek to mitigate. When an object loses its quantum properties and starts behaving like a classical object (i.e. ordinary objects whose behaviour is governed by the laws of physics that one generally thinks of), that is known as decoherence.

Specifically, for superconducting quantum devices and circuits, there exists an energy gap protecting the coherence of the objects against thermal energy. The larger the gap, the more protected the quantum object is against decoherence. When quantum materials, such as Twister Bilayer Graphene (TBG), have a better superconducting gap, it directly entitles stronger magnetism and superconductivity due to enhanced electron correlations. TBG can generate superconductivity due to flat bands.

Dr. Guo-Xing Miao, Institute for Quantum Computing (IQC) faculty and professor, Department of Electrical and Computer Engineering, and colleagues at the University of British Columbia (UBC) have reported a novel material platform where flat bands universally emerge in a wide range of Transition Metal Dichalcogenide (TMD) compounds.

This outcome is achieved through intercalation, which refers to the reversible insertion of ions into the host lattice. The researchers showed that not only can the flat bands be generated in the TMD compounds, but the position of the flat bands can also be adjusted on the energy scale.