High Energy Physics

Condensed Matter , Liquid Crystal

1. Mukherjee, P.K. and Das, A. K. (2016): Dielectric properties near the isotropic-smectic-C* phase transition.

Soft Materials 14, 199-203.

2. Mukherjee, P. K. and Das, A.K. (2016): Fluctuation induced of dielectric permittivity in the isotropic phase of cholesteric liquid crystals.

Int. J. Mod. Phys. B 30, 1650053-1-5.

3. Das, A.K. and Mukherjee, P. K. (2009): Phenomenological theory of the direct isotropic to hexatic B phase transition.

J. Chem Phys. 130, 054901-1-5.

4. Mukherjee, P. K. and Das, A.K. (2008): Non-linear dielectric effect in the isotropic phase of ferroelectric liquid crystals.

Physica B 403, 3089-.3092

5. Mukherjee, P. K. and Das, A.K. (2008): Linear dielectric response of antiferroelectric liquid crystals.

Physica B 403, 3627-3630.

6. Das, A. K. and Mukherjee, P. K. (2008): Tricritical behavior of the SmA-SmC transition in a liquid crystal mixture, Journal of Chemical Physics, 128, 234907

Research Statement:

Areas of my research is, to study theoretically the phase transition among the different liquid crystalline phases using Landau theory. A brief summary of my research work is given below:

All of us are well-known about the two extreme forms of condensed matter: homogeneous isotropic liquids and crystalline solids, the former have an average structure that is invariant under arbitrary rotations and translations whereas the latter have average structure that are invariant only w. r. t. certain discrete lattice translations and point group operations. The liquid state has no long range order and hence having highest possible symmetry whereas the crystalline solid state has long range positional and rotational order and hence having the lowest possible symmetry. Liquid crystals are the materials that lies between these two extreme states of matters and hence have mechanical and physical properties are intermediate between those of a liquid and those of a crystal. For example, liquid crystals possess high fluidity and do not support shear and at the same time they have anisotropic magnetic and electric susceptibilities.

Though there are basically two approaches in the study of phase transition, one is Landau mean field theory and the other is renormalization group theory, the previous one is the most suitable for the phenomenological description of liquid crystal phase transition for several reasons given below.

The first reason is the symmetry aspects which is the central theme of Landau theory. Besides that, to describe the physical behaviour of the system Landau theory is expected to be held in a limited range below the transition temperature if the discontinuities at the transition temperature are small enough. The interactions between different degrees of freedom and the number of adjustable phenomenological co-efficients which are expressed explicitly in the Landau theory determine the laws governing the behaviour of the different physical quantities.

The importance of Landau theory lies in the fact that it utilizes the statistical theory of critical phenomena. As Landau theory consists of the determinations of the equilibrium values of the order parameters at any fixed temperature and the fluctuations about that value, statistical theory works very well on this set of degrees of freedom.

Among the different intermediate phases observed in liquid crystal systems the most complex one is the smectic class in which there are many phases identified still now, however, the best understood smectic phases are smectic-A (SmA),smectic-C (SmC), smectic-B or hexatic smectic phases.

Extra-curricular Activities :

Perform as Course-Coordinator of Value Edn Certificate Course

Our College introduced Value education course since 5th December, 2015 and the authority bestowed the responsibility on me to construct the syllabus and conduct the course. Any student, faculties from any discipline may join the course for the upliftment of mental strength, to grow/inculcate the different value-sense within every individual humane. Since 21st June,2021 this course has been started by the IQAC as an outreached program to include external individual from all sections of society, with extended modified syllabus consistent with CBCS system.

I had been initiated on the 5th March Tuesday Dol-Purnima / Gour-Purnima tithi,1996 to Dr. Sri Mahanambrata Brahmachari, M.A. 1st class 1st, Sanskrit (Gold Med. in Nayadarshana) , M.A. in Philosophy (CU), Ph.D. in Bengal School of Gaudiya Philosophy, from Chicago University, USA (1938), Representative from India in 2nd Parliament of Religion ( World Fellowship of Faiths ) in chicago in 1933, authored on more than 50 books on metaphysical issues in bengali-Sanskrit-english. For brief click here

Starting from the formation of the required syllabus and preparation of the study material with ppt presentation for the Value Education Course, the most part of the presentation, specially the philosophical part is prepared with the help of PhD Thesis-উপনিষৎ ভাবনা-ব্রহ্মসূত্র-বেদ বিচিন্তন of my Revered Preceptor and so I take this opportunity to express my deep gratitude and indebtedness to Sri Gurudeva for his guidance, constant inspiration in my mind-intellect-heart.