Semiconductors galore!
Nanometer scale semiconductor devices

Controlling electrons is like playing stop and go

Controlling electrons is like playing stop and go
Electron spin distribution modelled in gallium arsenide

Electron spin distribution modelled in gallium arsenide
Semiconductor dots (electron microscope image)

Semiconductor dots (electron microscope image)
Quantum mechanics deals with wavefunctions

Quantum mechanics deals with wavefunctions
Electron temperature map in a quantum hall junction

Electron temperature map in a quantum hall junction
Quantum gate in a quantum computer

Quantum gate in a quantum computer
Ultrafast optical spectroscopy used to probe a gallium nitride crystal

Ultrafast optical spectroscopy used to probe a gallium nitride crystal

* Click image to enlarge.

What makes your iPod work? Why semiconductors of course. Without them electronics would not exist as you know it.

Electrons in semiconductors behave in ways we can exploit to make gates through which electrons can stop or go only with the permission of other electrons. That allows us to build memories, switches and processing circuits.

We are pushing the size of such devices to ever smaller dimensions in our Graduate School, down to tiny atomic-sized dots or lines. We are also implementing ultrafast optical methods to probe such structures.

Dots: only a few atoms across, tiny islands of semiconductors have properties totally different from bigger samples. Each behaves like an atom in itself.

We are investigating new ways to grow dots in precise arrays, to provide parts for entirely new machines such as a quantum computer.

Quantum devices: By confining electrons to a two-dimensional region and applying a magnetic field, one can observe quantized jumps in the electric field. This phenomenon, known as the quantum Hall effect, is being put to good use to design new quantum devices in our Graduate School.

Alternatively, by exploiting the spin of electrons, an intrinsically quantum phenomenon, we are designing new types of transistor devices.

Quantum computer: Using the laws of quantum mechanics that apply to tiny objects, unimaginably strange machines can be built. One example is a quantum computer, predicted to be superfast.

Existing only on paper, this dream is rapidly becoming a reality. We are investigating the use of semiconductor dots to make gates for quantum computers.