Strain-Induced Berry Phase in GaSb Microcrystals

The transverse and longitudinal magnetoresistances of GaSb microcrystals with tellurium doping concentration of 1.7 × 10 cm under the influence of uniaxial compression strain were studied in high magnetic fields of 0–14 T. Low-temperature Shubnikov–de Haas oscillations were observed for unstrained and strained n-type conductivity GaSb microcrystals in the whole range of the magnetic fields. The magnetoresistance oscillation amplitude decreases with the temperature increasing in the range of 4.2–30 K. The Shubnikov–de Haas oscillation period was changed due to the strain influence, and it was found to be 0.039 T. The emergence of the splitting at a magnetic field of about 7 T was revealed in the longitudinal magnetoresistance of GaSb microcrystals doped to a concentration in the vicinity of the metal–insulator transition. The value of the g-factor was found in the strained samples, and it has a value of 53. The strain influence on the effective mass of the electron m and the Dingle temperature T were also studied. The appearance of the Berry phase caused by the strain was revealed in GaSb microcrystals allowing their transition to the topological insulator state.