Hall Effect characterisation

Let’s start with a double gated Hall bar. The two gates are connected to a keithley 2600 series sourcemeter. We source a current with a lock-in MFLI (say, id 4400, and we measure the longitudinal resistance with the same lock-in, and the Hall resistance with another one, say 4401. The magnet is an Oxford Instruments triton.

Initialisation

import mesoscopy
mesoscopy.init_db('../database_hallbar.db')
exp = mesoscopy.create_exp(
     experiment_name='Hall bar gate dependence',
     sample_name='test sample'
)
station = mesoscopy.init_station(
     '4400', '4401',
     SMU_addr='TCPIP::192.168.0.1::inst0::INSTR',
     triton_addr='192.168.0.2'
)

mesoscopy.init_smu(
     station,
     limits_v=[16,48],
     max_rate=[.08,.12]
)
mesoscopy.init_lockin(
     station,
     freq=117,
     ampl=1,
     filterorder=8)

Density calibration

Gate map

Fan diagram at constant displacement