Quantum Information Experiments Using Few Electrons in Semiconductor Quantum Dots


Dohun Kim, Seoul National University


2018.11.07 15:00-16:00


Room 111, Physics Building


The charge and spin degrees of freedom of an electron constitute natural bases for constructing quantum two level systems, or qubits, in semiconductor quantum dots. The quantum dot charge qubit offers a simple architecture and high-speed operation, but generally suffers from fast dephasing due to strong coupling of the environment to the electron’s charge. On the other hand, quantum dot spin qubits have demonstrated long coherence times, but their manipulation is often slower than desired for important future applications. This talk will review experimental progress of fast semiconductor based quantum qubits, including single dot spin qubits, charge qubits and recently developed ‘hybrid’ qubits formed by three electrons in Si/SiGe double quantum dots or GaAs. Starting from discussing general introduction to quantum transport measurements in quantum dots, circuit design, and material issues for developing highly coherent qubits, the talk will focus on discussing implementations of advanced quantum measurement and validation protocols, largely adopting techniques developed in superconducting qubits and nuclear magnetic resonance research fields.