Control of Elementary Excitations by Acoustic Fields

Indirect excitons in confined acoustic potentials

A spatially indirect exciton (IX) is a bound state of an electron and a hole localized in different quantum wells of a double quantum well structure (DQW). The spatial separation, which is induced by an external field, has two main effects: from one side, it increases the exciton lifetime up to microseconds; on the other side, one has the formation of an electric dipole, which enhances the non linear properties of the exciton fluid coming from the particle-particle interaction. Due to this characteristics, IXs are particularly interesting for applications in optoelectronic devices. In this framework, the transport, as well as the manipulation of IXs fluid represents a fundamental achievement. 


The aim of this research project is to transport and manipulate IX with the travelling bandgap modulation induced by non piezoelectric SAWs, as well as studying the spectroscopic properties of IXs and the transport dynamics. The moving modulation induced by the SAW strain field traps and transports the long-living IXs over distances up to one mm. Moreover, IXs can also be transferred between orthogonal SAW beams, via a moving array of potential dots created by the interference of  two orthogonal SAW beams, which captures the IXs from the incoming beam and transfers them to the other. These functionalities can be combined to realize an IX acoustic multiplexer (EXAM), a device which combines several optoelectronic functionalities on a single chip including photon to exciton and exciton to photon conversion, on/off switching using Exciton Optoelectronic Transistors EXOTs, IX (information) transport in moving acoustic potentials, signal multiplexing and logic operations. 


The potential dots also offer a reliable and tunable zero-potential  landscape for the study of collective behaviors  such as superfluidity and Bose Einstein condensation. 


This project is carried in collaboration with the University of Jerusalem (Prof. R. Rapaport) within the DFG project No. SA 598/9.

Selected Publications

4 Author C. Hubert , A. Hernández-Mínguez , K. Biermann , P. V. Santos

Indirect excitons in (111) GaAs double quantum wells

Source Superlattices Microstruct. , 108 , 51 ( 2017 )
DOI : 10.1016/j.spmi.2017.01.023 | 2893 Cite : Bibtex RIS
C. Hubert, A. Hernández-Mínguez, K. Biermann, and P. V. Santos

3 Author A. Violante , R. Hey , P. V. Santos

Coherent transport and manipulation of spins in indirect-exciton nanostructures

Source Phys. Rev. B , 91 , 125302 ( 2015 )
DOI : 10.1103/PhysRevB.91.125302 | Download: PDF | 2745 Cite : Bibtex RIS
A. Violante, R. Hey, and P. V. Santos

2 Author A. Violante , K. Cohen , S. Lazic , R. Hey , R. Rapaport , P. V. Santos

Dynamics of indirect exciton transport by moving acoustic fields

Source New J. Phys. , 16 , 033035 ( 2014 )
DOI : 10.1088/1367-2630/16/3/033035 | Download: PDF | 2553 Cite : Bibtex RIS
A. Violante, K. Cohen, S. Lazic, R. Hey, R. Rapaport, and P. V. Santos

1 Author S. Lazic , A. Violante , K. Cohen , R. Hey , R. Rapaport , P. V. Santos

Scalable interconnections for remote indirect exciton systems based on acoustic transport

Source Phys. Rev. B , 89 , 085313 ( 2014 )
DOI : 10.1103/PhysRevB.89.085313 | Download: PDF | 2542 Cite : Bibtex RIS
S. Lazic, A. Violante, K. Cohen, R. Hey, R. Rapaport, and P. V. Santos


Dr. Paulo V. Santos

Senior Scientist

+49 30 20377-221

lab: -360, -340, -343