Regensburg 2019 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 58: Superconductivity: Qubits 2

TT 58.13: Vortrag

Donnerstag, 4. April 2019, 18:15–18:30, Theater

Topological Frequency Pump with a Decohering Qubit — •Matthias Droth and David Carpentier — École Normale Supérieure de Lyon, 69007 Lyon, France

The underlying topological order of a physical device can lead to very robust phenomena. The most prominent example is the quantum Hall effect where measurement of the quantized transverse conductance σ_xy yields the conductance quantum e²/h with high accuracy [1,2]. We study topological protection in a system with a driven quantum bit that features a topological phase in frequency space. A recent theoretical work proposed to realize an analog of the half Bernevig-Hughes-Zhang (BHZ) model – which realizes a quantum Hall effect – in the frequency domain by driving periodically a quantum spin, leading to an effective time dependent Hamiltonian [3,4].

It is known that for such a realization of the half-BHZ model, the power transfer rate between the frequency drives, P_1→2, takes the role of σ_xy as the quantized and topologically protected quantity [4]. Here, we investigate the robustness of this quantization in a realistic setup that involves a decohering qubit.
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