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Optical Control and Info
rmation Processing in
Semiconductors
Semiconductor materials and nano-systems can be controlled at the quantum level using lasers. Our approach directly focuses on designing optical devices with a functional role
in memories, information processors, or network components. In particular, we work
on spins in quantum dots and diluted impurities, exploring theoretically how they can
be controlled at the quantum level using a laser field. We study optically-induced spin
coupling mechanisms that can be applied to the realization of quantum logic gates in
quantum computing architectures. These mechanisms can be used to induce ferromagnetic transitions in magnetic semiconductors, and may lead to new, non-dissipative and
reversible methods of computation and data storage, based on light.
Carlo Piermarocchi
Theoretical Condensed
Matter Physics
ASSOCIATE PROFESSOR
M.S., 1994
Swiss Federal Institute of Technology (EPFL)
Lausanne, Switzerland
Ph.D., 1998,
University of Pisa, Italy
Joined CMP group: 2002
SELECTED PUBLICATIONS
M. J. A. Schuetz, M. G. Moore, and C. Piermarocchi, Trionic Optical Potential for Electrons in Semiconductors, Nature Physics 6, 919
(2010).
Fig.1. Optical lattices in semiconductors: scheme for electron trapping in quantum wells using interfering
laser beams. Electrons are trapped by the light due to the presence of three-body resonances in a semiconductor material. M. J. A. Schuetz, M. G. Moore, and C. Piermarocchi, Trionic Optical Potential for
Electrons in Semiconductors, Nature Physics 6, 919 (2010).
Exciton and Polariton Optics We are interested in the properties and the dynamics of optical
excitations in semiconductors (excitons) in confined and/or periodic nanostructures, such as
quantum wells, quantum wires, or arrays of quantum dots. Cavity polaritons are states resulting from the strong coupling of excitons with photons in an electromagnetic cavity. Both
excitons and cavity polaritons are candidate for the realization Bose Einstein condensates
in semiconductors. We are interested in studying how excitons and polaritons interact with
phonons and how their radiative energy transfer and phonon dissipation can be controlled
in different nanostructures. A fundamental understanding of exciton energy transfer could
lead to innovative device architectures able to control more efficiently the flow of energy,
enhance light extraction/collection, and minimize thermal and radiative losses.
M. D. Kapetanakis, I. E. Perakis, K. J. Wickey,
C. Piermarocchi, and J. Wang, Femtosecond
coherent control of spins in (Ga,Mn)As ferromagnetic semiconductors using light, Phys.
Rev. Lett. 103, 047404 (2009).
G. Quinteiro Rosen, J. Fernandez-Rossier, and
C. Piermarocchi, Long-range spin-qubit interaction mediated by microcavity polaritons,
Phys. Rev. Lett. 97, 097401 (2006).
D. Calzolari, G. Paternostro, P. L. Harrington
Jr. , C. Piermarocchi, and P. M. Duxbury, Selective control of the apoptosis network in heterogeneous cell populations, PLoS ONE 2(6):
e547, (2007).
Signaling in Complex Biological Networks We work on the control theory of signaling networks in cells based on concepts from statistical physics and information theory. In a cell,
the flow of information is regulated by many different processes such as transcription and
its regulation by transcription factors, molecular modifications, change in concentration of
substances, as well as stimuli such as heat or light. This complex behavior is described by
signal transduction networks in which nodes are typically proteins or other agents, and edges
denote inhibition or stimulation. Statistical physics and information theory ideas including
entropy, frustration, metastability and non-equilibrium processes are common to spin systems and to signaling biological networks. For example, spin glasses are characterized by
the competition of ferromagnetic and anti-ferromagnetic interactions, leading to frustration
and to the emergence of different macroscopic phases. Similarly, the competition between
inhibition and stimulation in complex signaling networks can lead to glassy behavior, which
in biology is linked to robustness and evolvability
[email protected]
power.pa.msu.edu/profile/carlo