| 1. |
- Xiao, S., et al.
(författare)
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Talking through the continuum : New manifestations of Fano-resonance phenomenology realized with mesoscopic nanostructures
- 2013
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Ingår i: Fortschritte der Physik. - : Wiley. - 0015-8208 .- 1521-3978. ; 61:2-3, s. 348-359
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Tidskriftsartikel (refereegranskat)abstract
- The focus of this review is recent work in which we have demonstrated a highly-flexible approach to the study of Fano-resonance phenomena, by making use of the mesoscopic devices known as quantum point contacts (QPCs). Utilizing the ability of these structures to function as an on-demand quantum state, we demonstrate a highly-flexible system for the investigation of Fano resonances. Our approach involves making measurements of non-locally coupled pairs of QPCs, one of which is used to form the discrete state needed for the Fano resonance, while the other serves as a detector whose conductance is sensitive to the energy of this state. As a demonstration of the flexibility of this approach, we show how it can be used to implement a multi-state Fano resonance, in which two discrete states undergo a robust interaction that is achieved by coupling them to each other through a common continuum.
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| 2. |
- Yoon, Y., et al.
(författare)
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Coupling Quantum States through a Continuum : A Mesoscopic Multistate Fano Resonance
- 2012
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Ingår i: Physical Review X. - 2160-3308. ; 2:2, s. 021003-
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate a fully tunable realization of a multistate Fano resonance, in which a pair of remote quantum states experience an effective coupling due to their mutual overlap with a continuum. Our mesoscopic implementation of this system exploits the ability of the semiconductor nanostructures known as quantum point contacts (QPCs) to serve, in the low-density limit close to pinch-off, as an on-demand localized state. By coupling the states formed on two separate QPCs, through a two-dimensional electron gas that serves as a continuum, we observe a robust effective interaction between the QPCs. To explain this result, we develop a theoretical formulation, based on the ideas of the Schrieffer-Wolff transformation, which is able to reproduce our key experimental findings. According to this model, the robust character of the interaction between the two remote states arises from the fact that the interaction is essentially mediated by a large number of degenerate continuum states. While the continuum is often viewed as a source of decoherence, our experiment therefore instead suggests the possibility of using this medium to support the interaction of quantum states, a result that may allow new approaches to coherently couple nanostructures in extended geometries.
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