## Theoretical Condensed Matter Physics

### Adrian Feiguin

Assistant Professor

PhD Universidad Nacional de Rosario (Argentina), 2000

(617) 373-2925

a.feiguin@neu.edu

### Research Summary

Prof. Adrian Feiguin’s field of expertise is computational condensed matter, focusing on quantum mechanical problems with strong correlations. He conducts research on several topics ranging from quantum transport, to exotic phases of matter in cold atom systems.

In modern condensed matter theory, the study of strongly correlated systems occupies the foremost area of research.

This is motivated by the rich and exotic physics that emerges when the interactions in a quantum system are strong. When interactions behave non-pertubatively, they give rise some complex and intriguing phenomena, such as the Kondo effect, spin-charge separation, charge fractionalization, and fractional quantum statistics.

Studying solid state systems can be extremely challenging, both theoretical and experimentally, with macroscopic number of degrees of freedom, disorder, unknown interactions… Moreover, all of these phenomena occur under very extreme conditions, such as extremely low temperatures, high pressure, and/or high magnetic fields. It is in these regimes where the quantum nature of matter dominates its behavior.

In highly correlated problems, analytical techniques are difficult to control and many times lead to misleading results. For this reason, and motivated by the rich physics emerging from strong interactions, the past decades have seen an explosion of activity around computational condensed matter, and numerical methods have experienced a remarkable evolution, shedding light on long-standing problems, and usually providing answers to the most difficult questions.

In broad terms some the research topics being studied in Prof. Feiguin’s group are:

-Time-dependent and non-equilibrium quantum behavior.

-Electronic and spin transport in mesoscopic systems.

-Exotic phases in ultraccold atomic gases.

-Decoherence in quantum systems, including N-V centers in diamond.

-Quantum Magnetism in low dimensions.

-Exotic quantum phases of matter and topological order, including high temperature superconductivity and the fractional quantum Hall effect.

### Relevant Publications:

“Magnetostriction and Magnetic Texture to 100.75 Tesla in Frustrated SrCu_{2}(BO_{3})_{2}” Marcelo Jaime, Ramzy Daou, Scott Crooker, Dagmar F. Weickert, Atsuko Uchida, Adrian Feiguin, Cristian D. Batista, H. Dabkowska and B. Gaulin PNAS, In Press (2012)

“Spin-Incoherent Behavior in the Ground State of Strongly Correlated Systems” Adrian E. Feiguin, Gregory A. Fiete. Phys. Rev. Lett. **106**, 186802 (2011).

“How to Find Conductance Tensors of Quantum Multi-Wire Junctions Through Static Calculations: Application to an Interacting Y-Junction” Armin Rahmani, Chang-Yu Hou, Adrian Feiguin, Claudio Chamon, and Ian Affleck. Phys. Rev. Lett. **105**, 226803 (2010).

Dynamics of a Single Spin Interacting with an Adjustable Spin Bath” R. Hanson, V.V. Dobrovitski, A.E. Feiguin, O. Gywat and D.D. Awschalom. Science 18 April 2008 320: 352-355

“Real Time Evolution using the Density Matrix Renormalization Group” Steven R. White and Adrian E. Feiguin. Phys. Rev. Lett. **93**, 076401 (2004)