ABC...z Seminar Series: Thursday, November 29th: Electrical generation and detection of spin waves in a quantum Hall ferromagnet

Event Date: 

Thursday, November 29, 2018 - 3:45pm

Event Date Details: 

Light refreshments Served at 3:30pm.

Event Location: 

  • Broida 1640
  • ABC...z Seminar Series

Spin waves are collective excitations of magnetic systems. An attractive setting for studying long-lived spin-wave physics is the quantum Hall (QH) ferromagnet, which forms spontaneously in clean two-dimensional electron systems at low temperature and in a perpendicular magnetic field. We used out-of-equilibrium occupation of QH edge channels in graphene to excite and detect spin waves in magnetically ordered QH states. Our experiments provide direct evidence for long-distance spin-wave propagation through different ferromagnetic phases in the N = 0 Landau level, as well as across the insulating canted antiferromagnetic phase. Our results will enable experimental investigation of the fundamental magnetic properties o these exotic two-dimensional electron systems.

Didi Wei, Harvard University