ITR: Optical Control in Semiconductors for Spintronics and Quantum Information Processing

Supported by National Science Foundation, Division of Materials Research, Condensed Matter Physics Program, Program Officer: Dr. Hollis Wickman, Grant No. DMR-0325474, September 15, 2003 – August 31, 2008

PIs: J. Kono (Rice University), H. Munekata (Tokyo Institute of Technology), Lu J. Sham (University of California, San Diego), D. H. Reitze, G. D. Sanders, and C. J. Stanton (University of Florida).

Kick-Off Meeting

 

Project Summary | Background | Project Description | References Cited


 

Project Summary

The goal of this ITR program is to develop ultrafast optical methods for controlling electronic, magnetic, vibrational, and excitonic properties of semiconductors for fast information processing.  Successful manipulation of quantum states and processes in solids – quantum engineered semiconductor structures in particular – will be a necessary breakthrough for implementing the emerging technologies of spintronics and quantum information science.  Optical control, as opposed to electrical control, has the advantage of performing quantum control on femtosecond time scales, which we will explore in the following four specific contexts:

1) Optical control of ferromagnetism in magnetic III-V semiconductors: we will investigate ultrafast magnetization reversal processes in carrier-induced ferromagnetism using real and virtual carriers by above and below bandgap excitations; 2) optical control of band structure using the dynamic Franz-Keldysh effect: we will non-perturbatively modify electronic states with ultrashort pulses of long-wavelength light, which leads to ultrafast photoinduced absorption and transparency; 3) optical control of electric fields in GaN/InGaN strain superlattices: we will excite coherent, localized phonon wavepackets which, through ultrafast alteration of the huge built-in piezo electric fields, produces coherent terahertz waves; 4) optical control of excitons in coupled quantum wells: we will demonstrate quantum gates based upon ultrafast optical control of coherent tunneling of charge carriers in coupled quantum wells separated by tunneling barriers.

We have formed a unique, interdisciplinary team to conduct this innovative research, consisting of three experimentalists and three theorists.  A key feature is our {\it combined expertise} in molecular-beam epitaxy, optical and terahertz spectroscopy, ultrafast optical phenomena and pulse shaping, many-body theory, and theory of electronic, optical and magnetic properties.  {\it Each investigator could not separately accomplish all of the objectives of this program alone}.

The proposed research work will train undergraduate and graduate researchers in frontier projects in nanoscience and quantum information science to produce quantum scientists and engineers with a wide and strong background in spectroscopy, optics, photonics, solid state theory, many-body theory, and quantum information theory.  New courses on nanotechnology and quantum information science will be developed in the Applied Physics curricula at Rice University, the University of Florida, and the University of California at San Diego.

The intellectual merit of the proposed activity includes: increased understanding of the quantum states and dynamics of interacting, non-equilibrium, or strongly driven carriers in nanostructures; establishment of the quantum nature of exciton-light interaction; and provision of a controlled environment in which to address unanswered questions in many-body physics.  The broader impacts resulting from the proposed activity include: increased students' readiness for the fast-paced world of modern nanotechnology; new spectroscopy techniques; novel device concepts and implementations.


Background

Under construction


Project Description

Under construction

 


References Cited

 

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