This award supports theoretical research and education on anisotropic phases of strongly correlated two-dimensional electronic systems in quantum Hall states. The PI aims to elucidate the origin and the stabilization of various intermediate phases purported to have liquid crystalline order. Though anisotropic electronic phases in high mobility GaAs/AlGaAs hetero-structures were discovered experimentally nearly ten years ago, their ultimate nature remains elusive. Experiments show anisotropy arises only below a critical temperature of about 100 mK and is observed only in high Landau levels. A key aspect of anisotropic electronic phases that lacks understanding is the consistent orientation of such phases with respect to the crystalline axes of the host GaAs crystal lattice.
The PI takes the view that the emergence of magneto-transport anisotropy is an indicator that electrons have formed a novel electronic phase with liquid crystalline order. The PI aims to investigate outstanding fundamental issues, including: (i) the microscopic origin of anisotropy; (ii) the nature of liquid crystalline states in high Landau levels in perpendicular magnetic field; (iii) the physical mechanism of stabilization of anisotropic liquid crystalline phases in high Landau levels; (iv) the role played by an anisotropic electron-electron perturbation to orient and stabilize various anisotropic phases; and (v) the existence of anisotropic liquid crystalline phases in the lowest Landau level at low temperature stabilized by the combined effect of a weak substrate-mediated anisotropic electron-electron perturbation and a tilted magnetic field.
Numerical and quantum Monte Carlo calculations will be performed to address outstanding questions about anisotropy in the quantum Hall regime. The research will contribute to a better theoretical understanding of quantum phase transitions and various novel liquid crystalline or hybrid phases in strongly correlated electronic systems in low dimensions.
Undergraduate students will be able to participate in valuable research experiences. This award will further help to enhance research and education infrastructure for underrepresented minority students at a minority HBCU institution. Through an outreach activity, the PI aims to develop interest in science related areas at the K-12 level in underprivileged local communities and local high schools.
NON-TECHNICAL SUMMARY:
This award supports theoretical research and education with an aim to understand new states of matter exhibited by electrons in high magnetic fields and confined to a plane. Cleverly engineered structures made of semiconductor materials can hold electrons in two dimensions. The PI will use advanced computer simulation and theoretical methods to elucidate the quantum mechanical state of electrons in these structures when placed in a high magnetic field. Unlike gases of atoms or even electrons in a copper wire, electrons in these states behave in a cooperative way that is choreographed by quantum mechanics. The PI seeks to investigate intriguing states that are believed to be analogous to phases of long molecules -- phases that have the sense of a particular direction and are related to the ones in a liquid crystal display. The PI suggests that these liquid crystal like states of electrons can appear under specific circumstances not yet explored by experiments.
New electronic states of matter are interesting from the perspective of fundamental science, but are also potential building blocks of future technologies for electronic devices, sensors, computation, and more.
Undergraduate students will be able to participate in valuable research experiences. This award will further help to enhance research and education infrastructure for underrepresented minority students at a minority HBCU institution. Through an outreach activity, the PI aims to develop interest in science related areas at the K-12 level in underprivileged local communities and local high schools.
We conducted theoretical research and education activities tailored towards the aim of understanding new states of matter exhibited by systems of interacting electrons in high magnetic field and confined to a plane. Cleverly engineered structures made of semiconductor materials can hold electrons in two dimensions. We used advanced computer simulation and theoretical methods to elucidate the quantum mechanical state of electrons in these structures when placed in a high magnetic field. Unlike the electrons in a copper wire, electrons in these states behave in a cooperative way that is choreographed by the laws of quantum mechanics. In this project we investigated intriguing anisotropic many-electronic states that are believed to be analogous to phases of long molecules - phases that have the sense of a particular direction and are related to the ones in a liquid crystal display. These liquid crystal like states of electrons can appear under specific circumstances and are interesting not only from the perspective of fundamental science, but are also potential building blocks of future technologies for electronic devices, sensors computation, and more. This project also involved several undergraduate students who were able to participate in valuable research experiences. Through this project we contributed to enhance research and education infrastructure for undergraduate students including a large proportion of underrepresented minority students at a minority HBCU institution. Through outreach activities, we contributed to develop interest in science related areas at the K-12 level in local communities and local high schools.
