Quantum oscillations of $Cu_{x}Bi_{2}Se_{3}$ in intense magnetic field

Quantum oscillations are generally studied to resolve the electronic structure of topological insulators. Recently there has been much interest in resolving the Fermi Surface of $Cu_{x}Bi_{2}Se_{3}$ to shed light on the nature of its superconducting state - in particular to determine if it is a topological superconductor, an exotic class of material. Using torque magnetometry, quantum oscillations in magnetization (the de Haas--van Alphen effect) were observed [1] in $Cu_{x}Bi_{2}Se_{3}$ up to 90 degrees in polar angle with respect to the sample surface. The doping of Cu in $Bi_{2}Se_{3}$ increases the carrier density and its ellipsoidal Fermi Surface becomes increasingly elongated. The detailed study of the temperature dependence at different tilt angles reveals strong effective mass anisotropy. The comparison of oscillation data in magnetization with that in magnetoresistance [2] helps elucidate the electronic structure of this interesting material. \\[4pt] [1] B.J. Lawson, Y.S. Hor, Lu Li, Phys. Rev. Lett. {\bf 109}, 226406 (2012).\\[0pt] [2] E. Lahoud, {\it et al.}, Phys. Rev. B {\bf 88}, 195107 (2013).