Princeton Center for Complex Materials

James Sturm (Electrical Engineering)
Jeff Schwartz (Chemistry)
Antoine Kahn (Electrical Engineering)
Sigurd Wagner (Electrical Engineering)

7/1/2012-

This seed aims to make structures which selectively control the motion of electrons and holes in and out of silicon, and in many cases electrons vs. holes based on the relative offsets of the valence and  conduction bands in the two materials. A high conduction band in the metal oxide on Si will block electrons from entering or leaving the Si (ideally with NiO), and a low valence band will block holes (e.g. TiO₂). This control has wide applications in electronics for conventional devices (photovoltaics, transistors) and in emerging devices, such as enhancement mode Si-based 2DEG’s for quantum computing, where a high quality insulator deposited on silicon under 400°C is a top problem - under 400°C to prevent damage to the 2DEG -, and others.

Rodney Priestley (Chemical and Biological Engineering)
Pablo Debenedetti (Chemical and Biological Engineering)

7/1/2012-

This seed will develop experimental and computational approaches to investigate the viscoelastic properties of supported thin polymer films. In the Priestley lab, we are currently developing a non-contact method to measure the viscoelastic properties of supported thin polymer films. In the Debenedetti group, we plan to undertake complementary molecular-based computational studies involving supported thin films (10-50 nm) of united-atom representations of chain molecules.

Howard Stone (Mechanical and Aerospace Engineering)  
Richard Register (Chemical and Biological Engineering)

7/1/2012-

This seed will use the toolbox of microfluidics to investigate the role of topology on microphase separation of block copolymers confined to thin films. By continuously forming bubbles or drops in microfluidic devices, we will study the influence of the radius of curvature of the substrate and the influence of different surface boundary conditions associated with gas versus liquid interfaces.

James Sturm (Electrical Engineering)
Stephen Lyon (Electrical Engineering)
Jason Petta (Physics)

7/1/2012-

The spin decoherence time in naturally-occuring silicon is limited by the 4.7% of ²⁹Si (due to its nuclear spin) compared to 92.2% ²⁸Si and 3.1% ³⁰Si. At Princeton we have recently succeeded in growing the first high quality 2DEGs with isotopically-enriched ²⁸Si, so that the ²⁹Si level is decreased by ~20X to ~0.2%. In this project, we will (i) grow ²⁸Si Si/SiGe heterostructures as required to enable electron spin relaxation and coherence measurements in the ²⁸Si layers (Sturm) (ii) measure the spin lifetimes and coherence times by spin resonance (Lyon) and magneto transport (Petta). We hope to be the first group to experimentally confirm the potential of electrons in ²⁸Si in Si/SiGe heterostructures. Such a result would help move Princeton to a leading position in the Si-based QC field, and set the stage for future programs.

Garnet Kin-Lic Chan (Chemistry)
David Huse (Physics)

7/1/2012-

The rich behaviour of frustrated quantum systems continues both to puzzle and perplex theoreticians and experimentalists alike. A deeper understanding of quantum frustration is currently hindered by difficulties in experimentally realizing the theoretical models associated with many exotic ground states. The current seed proposal aims to bring theory and experiment in frustated quantum systems closer through (i) developing new numerical techniques, based on density matrix entanglement embedding, to simulate frustrated quantum Hamiltonians at a realistic ab-initio level, thus bringing theory closer to experiment, and (ii) using numerical simulations to rapidly screen phase diagrams for new lattices and interaction regimes. Our goal is to identify lattices and Hamiltonians which are both interesting and experimentally viable, thus bringing experiment closer to theory.

Rodney Priestley (Chemical and Biological Engineering)
Craig Arnold (Mechanical and Aerospace Engineering)
Lynn Loo (Chemical and Biological Engineering)

6/1/2011-11/30/2012

The PIs have investigated the structure and properties of olythiophene (P3HT) films prepared by a unique processing method termed, Matrix Assisted Pulsed Laser Evaporation (MAPLE). The goal of this initial study was to access MAPLE as a viable processing method to generate P3HT films with novel structures, not achievable by spin casting, and with different optoelectronic properties. An important question is whether new or “hidden” morphologies of P3HT films may be achieved via MAPLE deposition.

Publications

1. Y. Guo, A. Morozov, D. Schneider, J. W. Chung, C. Zhang, M. Waldmann, N. Yao, G. Fytas, C. B. Arnold and R. D. Priestley, “Ultrastable nanostructured polymer glasses”, Nature Materials 11, 337 DOI: 10.1038/NMAT3234 (2012).

Mark Brynildsen (Chemical and Biological Engineering)
Jamie Link (Chemical and Biological Engineering)

6/1/2011-11/30/2012

The goal of this project is to define physiology-material property relationships for biofilms at the systems-level. Bacterial metabolism (Aim 1) and RNA polymerase (RNAP) activity (Aim 2) were the two physiological parameters targeted for study, whereas surface morphology, adhesion, cohesion, and spring constants as measured by atomic force microscopy (AFM) were the material properties of interest.

Hakan Tureci (Electrical Engineering)
Andrew Houck (Electrical Engineering)

6/1/2011-11/30/2012

The groups led by Tureci and Houck focused on signatures of correlated behavior in small systems composed of (a) a strongly interacting 'photonic dot' and (b) two tunnel-coupled cQED cavities coupled to two leads. These initial investigations build the groundwork for future experiments on extended lattices for the simulation of non-equilibrium Hubbard models of interacting light-matter systems.

Publications

1. A.A. Houck, H. E. Tureci, and J. Koch, “On-chip quantum simulation with superconducting circuits”,   Nature Phys. 8, 292 (2012).

2. A.J. Hoffman, S.J. Srinivasan, S. Schmidt, L. Spietz, J. Aumentado, H.E. Tureci, A.A. Houck, “Dispersive Photon Blockade in a Superconducting Circuit”,   Phys. Rev. Lett. 107, 053602   (2011).

Naveen Verma (Electrical Engineering)
Sigurd Wagner (Electrical Engineering)

6/1/2011-5/31/2012

The focus of this research is the use of materials that actively promote tissue growth, allowing the engineered electronic systems to selectively incorporate regenerative properties both to enhance implantation as well as to promote the restoration of specific biological processes within the system. The material initially focused on is a purified, cross-linked matrix of Type-1 collagen. This material exhibits regenerative properties for a range of tissue.