The main focus of the femtolab is in using ultrafast (femtosecond) lasers for molecular control and decoherence which will give rise to all kinds of effects which can have implications to various fundamental as well as applied areas of research including biomedical areas. Here a perspective of evolving area of physical chemistry that could impact the future of information and has implications on various fundamental as well as applied areas of research including biomolecular applications is presented.

Coherent control of decoherence: Quantum Computing:

Control of molecular reaction directs vibronically excited molecular systems into specific reaction pathways. Failure through such molecular control through laser selective excitation arises from decoherence and dephasing of coherence. Minimizing decoherence is also an important challenge towards realizing quantum computing and quantum information. Typical molecular vibrations occur in picoseconds. So it is important to have control parameters in femtoseconds. Population transfer in molecules involves multiple states besides the radiative coupled two labels which undergo quantum interferences resulting in decoherences. Coupling to the non radiative channels can however be minimized to robustly controlled decoherence through destructive quantum interference between the multiple excitation pathways. Thus a useful quantification of controllability can be identified in terms of two label of character in a multilevel system through density matrix evaluation of coherent character of quantum states. Only a synergy of molecular dynamics and spatio-temporal control of molecules embodies the future of quantum information and computing. It turns out that the very oddly separated areas become connected. Because of that Quantum computing on very odd end gets connected because there also you need 100% controllability as well as 100% both spatial and temporal controllability. And we want to do with optics only. Now light has many more implications. You can actually encode light by informing, putting in data. So there are some data communication issues also which we can bring in, which is generally not what we basically work on. Our data communication only stops at the point that we have informed the molecule what to do. We are not using that as an electrical data communication scheme any more. We had started that at some point of time but now we have moved into more into informing the molecule business. Now the molecule is supposed to take it further and that is the quantum aspect. Sometimes we are not interested in to see the take it further part. We are very happy with when we inform the molecule and get a response from it.

Molecular dynamics:

In our lab we go across different phases of matter: solids, liquids and gases. We have solids where we do studies in crystals and glass plates. We have looked at thin films. Then we go to liquids; we do dynamics of liquids, measure two-photon fluorescence, two-photon absorption, two-photon cross-sections etc. We have a molecular beam chamber. Also we work in interfaces which are between liquid-liquid, and liquid-solid. The basic idea behind doing this is, it has connection to biology. Another very interesting work is, how long phenomena effecting short term phenomena like temperature. Temperature as all know that is long term phenomena. But we have found that a long term phenomenon has important impact on short term phenomena. The important work in this direction started form the time of Mathies and Shank, where they showed that the ultimate concept of our vision which is in nanoseconds or longer actually starts at femtoseconds. They showed that the primary proton transfer process occurs in less than femtoseconds which is the trigger for the rhodopsin molecules to start the process of optical nerve firing and that finally gives rise to the image. We are interested in seeing how these eventual phenomena are actually connected.

Spatio-temporal control:

We are trying to go towards a direction where we are going to mix the temporal part with spatial part. Spatial part is the part where we talk about the biological imaging, controlling imaging i. e. the coherent control of bioimaging. It is in the spatial domain, but it has a coupling in the time domain also. In the spatial control, the biggest control that we have is the optical tweezer, where we hold something and have the capabilities of moving something in a controlled way. In our lab we have a tweezer which is pulsed in time. So we are imparting time and space simultaneously. Controlled spatial manipulation of controlling translational degrees of freedom of molecules is essential to achieve controlled intermolecular interactions for implementing molecular quantum logic. Instituting total such control therefore involves inducing an overall molecular polarizibility through femtosecond temporal modulations that is simultaneously amenable to spatial control through macroscopic aspects of light polarization, photon flux, manipulations etc. Our pulse shaper is a unique example where we convert between time and space in terms of Fourier transform. Again in terms of action we do the same thing, we convert time and space simultaneously. So actually we can think of Fourier domain-Fourier domain in spectroscopy, Fourier domain in microscopy and Fourier domain in control. One Fourier plane is generating the problem and the other Fourier plane where we are doing the problem essentially solving the problem. This is the overall view of the picture. Then there are different sub fields where the focus is now shifting on. These sub fields become as wide as quantum computing on one end and biological imaging at the other end. And then they get connected by chemistry somewhere in the middle .But since the overall picture has some connection with the all, we can take information from all these angles and can get it connected by some means or the other.