RESEARCH OVERVIEW
The group is focused on studying the transport properties of quantum devices, which are fabricated on a high mobility GaAs/AlGaAs semiconductor wafer. We design and fabricate unique quantum devices by using Quantum Point Contact, Quantum Dot, Aharonov-Bohm interferometers and etc. as building blocks. We are especially interested in studying quantum entanglement and many body interactions in qunatum devices. Also, we are developing a new type of logic gates by exploiting the quantum transport nature of quantum point contacts. Finally we are developing precision measurement systems to study shot noise, cross correlation and ultra low level current measurement and etc.
• Quantum entanglement
• Ondemand electron entangled pair generation
• Many body interactions in quantum dot system
• Frustated states in a Triple Quantum Dot.
• Logic gates based on Quantum Point Contact
• Development of precision transport measurement systems



RESEARCH FACILITIES

Dilution Refrigerator and 4K measurement system

The dilution refrigerator, with base temperature of less than 30mK is installed. The refrigerator is attached to the ultra low noise conductance measurement system, which is developed in our group. Also, 4K measurement system is installed.








Clean Room

The clean room is used to fabricate quantum devices. It is used to do optical lithography, thin film deposition, annealing and etc.
Clean Room Equipments
• Mask Aligner
• Wet Bench
• Thermal Evaporator
• Oxygen Plasma Cleaner
• Rapid Thermal Annealer



SEM and e-beam Writer

The state of art Scanning Electron Microscopy (SEM) from Zeiss is installed. On the machine, Raith Pattern Generator is attached for e-beam writing. The system is capable of writing the patterns down to 20nm in width.









FUTURE PROJECTS

Force-free Aharonv-Bohm Effect
We try to observe Aharonov-Bohm Effect when electron do not experience any external magnetic field.


Charge Frustration under B-field
We want to study how charge frustrated state evolves under external magnetic field


Electron Pair Tunneling
We are now developing a device based on triple quantum dot (TQD) which can show pair tunneling of electrons through TQD.


Single Electron Aharonv-Bohm Effect
We are developing a closed-loop interferometer with a single quantum dot attached at the entrance of the interferometer. We want to study the interference caused only by a single electron.


On-demand Entangled electron source
We are developing on-demand entangled electron source by using adiabatic electron pump.






AVAILABLE POSITIONS

The position for Ph.D. and Master course students is open. Please contact us by email.


The position for undergraduate students who want to conduct a small project in the lab is open for all year around.







Mesoscopic and Quantum Device Laboratory, Department of Physics, Pusan National University, Busan, 709-635, Republic of Korea
Designed and Maintained by Yunchul Chung. (29/JAN/2013)