Research Fellow wins two science awards

Suchitra Sebastian

Junior Research Fellow Suchitra Sebastian has just won both the IOP Moseley Medal and the IUPAP Young Scientist Medal 2012.

Suchitra is an experimental physicist who studies quantum phenomenon such as superconductivity and magnetism in novel materials.

She won the Institute of Physics (IOP) Moseley Medal and Prize for her 'important discoveries in frustrated quantum magnets, heavy fermion systems and high temperature semiconductors.'

The IOP award is given annually to early-career scientists for distinguished research in experimental physics. The winner receives a silver medal accompanied by a certificate and a prize of £1,000. Suchitra will receive the award at the IOP Awards Dinner at the Intercontinental Hotel, London, in October.

The Moseley Medal comes a month after the announcement (on 27 April) that Suchitra had won The International Union of Pure and Applied Physics (IUPAP) Young Scientist Medal in the field of magnetism.

The IUPAP Young Scientist prize is presented every three years. The recipient 'is expected to have displayed significant achievement and exceptional promise for future achievement' in experimental, theoretical, or computational physics.

The award includes a prize of €1,000 and a medal, which will be presented in July at the International Conference on Magnetism in Busan, Korea.

Citation for the IOP Moseley Medal and Prize

Suchitra Sebastian has made exciting experimental discoveries in the field of interacting electron systems. Her success is due to her insights and talent in combining materials synthesis with thermodynamic and transport measurements at low temperature, high magnetic field and high pressure.

In the field of frustrated quantum magnets, she discovered an unexpected and striking phenomenon known as “dimensional reduction” in BaCuSi2O6 in which the effective dimension of the magnetic lattice decreases with decreasing temperature. In a related system, SrCu2(BO3)2, she observed a remarkably rich structure consisting of sharp plateaus in the magnetisation versus applied magnetic field. This behaviour, reminiscent of the fractional quantum Hall effect, poses a new challenge to the theory of magnetic insulators. In the field of heavy fermion systems she discovered an unusual quantum phase transition in the f-electron antiferromagnet, CeIn3, associated with a change in the topology of the Fermi surface as a function of magnetic field at low temperatures. This phenomenon, known as the Lifshitz transition, occurs at a critical magnetic field unexpectedly well below the critical field at which anti-ferromagnetism is suppressed. Her findings are leading to a re-examination of the conventional description of the heavy fermion state in this and related materials.

In the field of high temperature superconductivity she has made three important contributions. First, she demonstrated the possibility of attaining high temperature superconductivity via pressure tuning alone, starting from a magnetic but nonsuperconducting state at ambient pressure in SrFe2As2 and BaFe2As2. Second, she observed via the evolution of the Fermi surface, a continuous quantum phase transition in an under-doped copper oxide superconductor YBa2Cu3Oy. Third, she discovered new components in the spectrum of quantum oscillations in underdoped YBa2Cu3Oy in high magnetic fields, which combined with other findings is leading to a realistic model of the Fermi surface for this important material.

See the IOP website.

2 July 2012