The Institute for the Frontier of Attosecond Science and Technology is dedicated to research, education and outreach of
attosecond physics and optics.
Mission
- Provide unique opportunities for faculty, scientists and students from COS and CREOL to closely collaborate in attosecond
science research.
- Create and disseminate new knowledge in attosecond physics by conducting, presenting, and publishing cutting-edge fundamental
and applied research.
- Develop next generation attosecond lasers for technology transfer and creating jobs in the State of Florida and the nation.
These goals and objectives reflect the spirit of the UCF mission statement and strategic plan in that the Institute
for the Frontier of Attosecond Science and Technology brings cutting-edge, impactful, research opportunities to the
university. It attracts outside collaboration, funding, and other opportunities that help feed the economic, cultural,
intellectual, and societal needs of the Central Florida community. New developments in attosecond laser technology resulting
from the institute’s research are beneficial to local, national, and global communities.
Rationale/Need
The field of ultrafast atomic, molecular, optical and plasma physics has experienced a revolution
in the last decade. Attosecond light sources, which were first demonstrated in 2001, provide new opportunities to expand
our understanding of interaction between electrons, as well as correlation between electron and nuclear motion. It has the
potential to generate a deeper understanding of how medicines interact within the human body and of catalytic processes
in new materials for energy harvest and storage. It can help us develop quantum computers and other electronic devices that
are much faster than the current technology. During the first decade of attosecond science, most the experiments were the
proof-of-principle type that demonstrated the power of the new light source. Entering the second decade, attosecond science
starts to address problems that are more and more complex. The urgently required high power, high repetition rate attosecond
sources cannot be developed by a single professor’s group. Consequently, large attosecond centers and facilities are being
developed around the world. Establishing an attosecond institute is a strategic move to ensure that UCF is a front runner
in this field.
The attosecond research and education at UCF are scattered in two units, COS and CREOL. Whereas faculty members in CREOL
have skills to develop the best high power lasers for driving attosecond generation, groups in the department of physics
are leaders of attosecond generation and applications. At the present time, there is no strategic planning and coordination
to maximum the competitiveness and productivity of UCF. The funding agencies in the US have established several large research
programs such as two MURIs and a DARPA to support attosecond research. Although an individual researcher, Zenghu Chang,
has been successful in obtaining these grants, it is extremely difficult for UCF to compete for even larger grants such
as the NSF Physics Frontier Center because the lack of critical mass.
The Institute for the Frontier of Attosecond Science and Technology (iFAST) has two participating
units: Department of Physics and CREOL. It will combine the strength of two colleges and provide a platform for conducting
cutting-edge attosecond research collaboratively, for educating students in attosecond physics and for outreach to underrepresented
groups. Our main goal in the near future is to establish a NSF Physics Frontier Center. In the long term, we will target
more large funding opportunities such as Basis Research Initiative (DoD), MURI and DARPA.
By establishing a center for collaborative research on attosecond science, the potential is created for major breakthroughs
in our understanding of the role of ultrafast electron dynamics in atomic physics, molecular physics and materials science.
By combining experiments with theoretical insight, our research on correlated electron dynamics can lead to novel physical
concepts, pictures, and descriptions of multi-electron dynamics with a rich prospect of applications in physics. The development
of better attosecond sources and experimental instrumentation will lead to new products that will enhance the competitiveness
of US industrial partners in the very demanding high-end ultrafast laser market. The institute will attract graduate students
and postdocs who may shape the future of attosecond science, and can embark on successful careers in industries.
Major Activities:
Since the early time of quantum mechanics, understanding electron correlation has always been a central theme in atomic
physics research. However, a complete theoretical description of interacting electrons is extremely challenging. Our research
will focus on dynamic correlation, i.e., the correlation of the movement of electrons. Dynamic correlation may be manifest
by phase shifts, time delays, and angular correlations, all of which take place on ultrashort (100s of attoseconds or less)
timescales. Hence the need to develop measurement and theoretical tools on attosecond dynamical timescales. We will focus
on the following 4 research topics.
- Autoionization Autoionization plays an important role in physics, chemistry, biology, and astrophysics. Fano resonances
are a prototypical example of correlated multielectron interaction processes. The asymmetric line-shape of scattering cross
sections originates from the interference between a background and a resonant scattering process. Fano resonances and the
direct time-resolved observation of their electron–electron interaction dynamics represent a main focus of current attosecond
research. We propose to study autoionization of atoms and molecules with attosecond transient absorption experiments and
theory.
- Two-photon double ionization Theoretical research on double ionization of helium with two attosecond photons revealed
that the effects of electron correlation can be surprisingly complex. Unraveling the intricacies of electron correlation
in this simple atom is critical to our understanding of similar processes in more complex systems. Numerical simulations
show that it is possible to disentangle the different processes occurring in such pulses by analyzing the final momentum
distribution of the ejected electrons. We propose to study such processes with Cold Target Recoil Ion Momentum Spectroscopy
(COLTRIMS) and velocity map imaging (VMI) using a high repetition rate laser. The high power and high repetition rate attosecond
source needed for conducting two-photon (nonlinear) coincidence experiments will be developed by the CREOL groups.
- Interatomic Coulomb Decay Interatomic (or intermolecular) Coulombic decay (ICD) is a relaxation mechanism in excited
molecules and clusters where electron correlation plays a fundamental role. The typical ICD lifetimes are in the order of
a few to a few tens of femtoseconds. So far, a time-resolved study on the ICD process has been done only theoretically.
Experimentally, the ICD has been investigated until now only using XUV radiation generated by synchrotron facilities. We
propose to perform time-resolved investigation of ICD using a pump–probe approach.
- Charge migration in biomolecules Theoretical work shows that a pure electronic charge rearrangement can be responsible
for ultrafast energy transfer in large molecules. The hole created at a specific site of the system can migrate on a timescale
of a few femtoseconds or even attoseconds over the entire molecule due to electron correlation. We propose to conduct UV
pump–XUV probe experiments to initiate and probe this mechanism in oligopeptides and other molecules. After the removal
of the electron by the UV pulse, an XUV attosecond pulse will be used to eject a second electron. The energy distribution
of the electron contains information about the charge migration.
The attosecond experimental facility will be used for demonstrations in the “Frontier of Ultrafast Optics” and “Attosecond
Laser Physics” courses to be offered. It allows students to enjoy the opportunity to touch base with the most advanced laser
technology. The institute plans to establish an outreach program to offer attosecond research experience for high school
students and teachers.