Charge sensing and controllable tunnel coupling in a Si/SiGe double quantum dot.
We report integrated charge sensing measurements on a Si/SiGe double quantum dot. The quantum dot is shown to be tunable from a single, large dot to a well-isolated double dot. Charge sensing measurements enable the extraction of the tunnel coupling t between the quantum dots as a function of the voltage on the top gates defining the device. Control of the voltage on a single such gate tunes the barrier separating the two dots. The measured tunnel coupling is an exponential function of the gate voltage. The ability to control t is an important step toward controlling spin qubits in silicon quantum dots.
Simmons
C B
CB
University of Wisconsin-Madison, Madison, Wisconsin 53706, USA. cbsimmons@wisc.edu
Thalakulam
Madhu
M
Rosemeyer
B M
BM
Van Bael
B J
BJ
Sackmann
E K
EK
Savage
D E
DE
Lagally
M G
MG
Joynt
R
R
Friesen
Mark
M
Coppersmith
S N
SN
Eriksson
M A
MA
D005857:Germanium / Q000737:chemistry*; D008422:Materials Testing; D036103:Nanotechnology; D010316:Particle Size; D045663:Quantum Dots; D012825:Silicon / Q000737:chemistry*; D013499:Surface Properties
D005857:Germanium; D012825:Silicon