Four-qubit device with mixed couplings.
We present the first experimental results on a device with more than two superconducting qubits. The circuit consists of four three-junction flux qubits, with simultaneous ferro- and antiferromagnetic coupling implemented using shared Josephson junctions. Its response, which is dominated by the ground state, is characterized using low-frequency impedance measurement with a superconducting tank circuit coupled to the qubits. The results are found to be in excellent agreement with the quantum-mechanical predictions.
Grajcar
M
M
Institute for Physical High Technology, P.O. Box 100239, D-07702 Jena, Germany.
Izmalkov
A
A
van der Ploeg
S H W
SH
Linzen
S
S
Plecenik
T
T
Wagner
Th
T
Hübner
U
U
Il'ichev
E
E
Meyer
H-G
HG
Smirnov
A Yu
AY
Love
Peter J
PJ
Maassen van den Brink
Alec
A
Amin
M H S
MH
Uchaikin
S
S
Zagoskin
A M
AM