From files last edited 2013-06-03 04:55:39. CMExp

Condensed Matter Experiment
at McMaster University



Recently Retired Faculty

Kari Dalnoki-Veress

I. David Brown

Bruce D. Gaulin

Malcolm F. Collins

Takashi Imai

W. Ross Datars

David E. Venus

Thomas Timusk

Derek Walton

Research Areas

The largest area of contemporary physics is experimental condensed matter physics. It is a field of physics where a graduate degree opens many different avenues. As well as leading to fundamental research at universities and research institutions, experimental condensed matter physics has important applications in the semiconductor and communications industry; in materials research, for products requiring desirable mechanical, electronic, magnetic, or other properties; and in the petroleum and chemical industry where there is interest in the reactivity of the surfaces of condensed matter.

The experimental condensed matter physics group at McMaster has a reputation as an active group involved in high quality, current research. We were delighted when Bertram Brockhouse, an emeritus professor in our group, was awarded the 1994 Nobel Prize for his pioneering work in neutron scattering. Physicists here work on an assortment of problems that are at the forefront of modern physics, either because they represent recent discoveries (e.g. conduction in nanowires, high temperature superconductors), or because they are classic, fundamental problems where progress can lead to understanding in a wide range of related areas (e.g. magnetic phases of matter). Further examples of current research in the group are spin glasses, frustrated and low-dimensional spin systems, model membranes, materials exhibiting colossal magnetoresistance, magnetism of ultrathin films and layered stuctures, helical and unusual magnetic phases, and ‘heavy fermion' metals and superconductors.

This diverse list of topics does not, perhaps, reflect the cohesiveness and cooperation within the group. Graduate students will find that research in experimental condensed matter physics falls into three broad areas. The first is the study of the structures into which matter condenses. This includes crystalline structure, magnetic arrangement, and the phase transitions that occur between these structures. Given the structure, it is important to determine the nature of the ground states and excitations of these systems. It is primarily the electronic and vibrational (phonon) states that are of interest, although, in some materials, more exotic states are possible. Finally, the material and transport properties are studied with the aim of understanding how they derive from these states. Experimental and theoretical physicists work together closely to analyse the results, so that a link between properties and structure can be established.

Research in all three of these areas is represented at McMaster, resulting in a well-rounded experimental group. The individual faculty members focus on different aspects of a problem to form a community of research directed toward its solution. One example is the high temperature superconductors. These compounds are grown at McMaster, and then probed with X-rays, neutrons, electrons, magnetic and electric fields, muons, and infrared light to learn their structure, phase transitions, allowed excitations, magnetic and conductive properties; all with the ultimate aim of unravelling their unique mechanism of becoming superconducting.

Condensed matter physicists at McMaster have an impressive array of facilities available to carry out these experiments. In addition to their own laboratories, they participate in McMaster's Brockhouse Institute for Materials Research (BIMR), where, along with chemists and engineers, they have access to excellent crystal growing, x-ray diffraction and electron microscopy facilities. Individual faculty members also have strong links with neutron, synchrotron radiation and muon beam facilities in Canada and around the world.

The condensed matter experimental group currently consists of Drs. Brown (bonding and structure), Collins (neutron scattering), Datars (electronic properties of materials), Gaulin (neutron and x-ray scattering), Greedan (solid state chemistry), T. Imai (condensed matter experiment, NMR spectroscopy), Luke (muon spin resonance), Timusk (infrared spectroscopy),Venus (surface physics and film magnetism), and Walton (disordered systems). Please come and visit our laboratories for an informal tour. It will become clear that McMaster provides outstanding opportunities for graduate studies in experimental condensed matter physics.