Extended group picture, June 26, 2014

At the Helm

Mansour Shayegan

My research group focuses primarily on the physics of semiconductors, with an emphasis on their electronic properties. Our work involves the growth of Gallium Arsenide/Aluminum Gallium Arsenide (GaAs/AlGaAs) heterostructures by molecular beam epitaxy, and studies of ballistic and quantum transport in these structures. Of particular interest are the many-body phenomena observed in these low-dimensional structures at low temperatures and high magnetic fields. Our research includes the fabrication, via molecular-beam epitaxy followed by various lithography techniques, of very clean (low-disorder) quantum-confined carrier systems, as well as measurements of their electronic transport properties. The systems we are studying, namely novel, high-quality, quasi-two-dimensional electron and hole systems in selectively doped GaAs/AlGaAs heterojunction structures, are among the cleanest carrier systems available. In these structures, the mobile carriers are spatially separated from the dopant (impurity) atoms to minimize scattering. As a result, the mean-free-path of carriers at low temperatures reaches several microns, allowing us to study ballistic and phase-coherent transport. Such structures also provide a crucial and important test bed for new many-body physics, since the dominant interaction at low temperatures is the repulsion between the electrons themselves. In our work, we study ballistic and phase-coherent transport, as well as many-body phenomena in a variety of structures such as superlattices, density-modulated systems, wide parabolic quantum wells, quantum wires and dots, and single- and multilayer electron and hole systems.

Current Members

Md. Shafayat Hossain, grad student

I am a fourth year graduate student in Mashgroup. I received my B.S. from Bangladesh University of Engineering and Technology. My current research broadly focuses on studying many-body phases at the half-filled Landau levels in AlAs and GaAs 2D electrons. Outside of my research works, I like travelling, especially in the mountains.

Edwin Chung, grad student

I am a graduate student co-advised by Loren Pfeiffer and Mansour Shayegan. I am interested in the growth and characterization of high quality AlAs samples.

Ma Meng, grad student

I'm a third year graduate student in Mashgroup. I received my B.S. degrees in physics and Joint Math&Econ in University of California San Diego in 2015. My current research interest is to investigate transport properties in various systems such as GaAs 2-dimensional electron and hole systems, as well as AlAs and InAs 2-dimensional electron systems.

Kevin Villegas Rosales, grad student

I am a third year graduate student working with Mansour Shayegan in the rich physics of density imbalance double quantum wells in which each of the quantum wells are contacted individually although they are 10 nm apart. I am also interest in the thermal properties of strongly interacting systems such as Composite Fermions. I did my B. Sc. Engineering Physics at the National University of Engineering in Peru.

Hao Deng, grad student

Past Members

M.A. Mueed

Now at MIT working with Prof. Jarrillo-Herrero

Insun Jo

Now at IBM.

Yang Liu

Now at Stanford University working with Prof. Manoharan.

Dobromir Kamburov

Now at Opex.

Javad Shabani

Now professor at NYU.

Medini Padmanabhan

Now professor at Rhode Island College

Aurelius Lewis Graninger (alg3@us.ibm.com)

Tayfun Gokmen (tgokmen@us.ibm.com)

Nathaniel Bishop (nbishop@sandia.gov)

Babur Habib (bhabib@princeton.EDU)

Oki Gunawan (ogunawan@princeton.EDU)

Kamran Vakili

Yakov Shkolnikov (yshkolnikov(at)exponent.edu)

Emanuel Tutuc (etutuc(at)us.ibm.com)

Etienne De Poortere (etienne(at)phys.columbia.edu)

Jean Heremans (heremans(at)vt.edu)

Tsong-Sheng Lay (tslay(at)mail.nsysu.edu.tw)

JengPing Lu (jplu(at)parc.xerox.com)

Hari Manoharan (manoharan(at)stanford.edu)

Sorin Melinte (melinte(at)dice.ucl.ac.be)

Stergios Papadakis (stergios.papadakis(at)jhuapl.edu)

Mike Santos (santos(at)mail.nhn.ou.edu)

Sanjeev Shukla (sanjeevs(at)us.ibm.com)

Yun-Wuu Suen (ysuen(at)phys.nchu.edu.tw)

Jeng-Bang Yau (jeng-bang.yau(at)yale.edu)