1 0 1 0255 spin up spin down

自旋量子位(1) • 傳統上，電腦以八個位元0 1可表示 0~255 • 電子自旋spin up 和spin down可以當位元表示來用 • 電子自旋天生可當qubits因 為其可同時表示 0~255 • Qubits are extremely delicate: stray interactions with their surroundings degrade the superpositions extremely quickly, typically converting them into random ordinary bits. NTU NEMS Laboratory

自旋量子位(2) • Classical Bit (Boolean) 0 or 1 Two states • Quantum Bit (Qubit)α| = 0>= += β| =1> “Infinite” number of states • “n Qubits is worth 2 n Boolean bits” NTU NEMS Laboratory

Hot-Electron Spin-Transistor(1) Ic的兩個控制參數 • EB和BC之間的偏壓 • 外加磁場 NTU NEMS Laboratory

Hot-Electron Spin-Transistor(2) 優點 • 高和低的barrier高度 使得Ic和Ib的比增加 • 基層厚度小於 5 nm NTU NEMS Laboratory

自旋電子共振電晶體(1) a Field Effect Transistor in which the channel resistance monitors electron spin resonance, and the resonance frequency is in turn controlled by the gate voltage. NTU NEMS Laboratory

自旋電子共振電晶體(2) • J-exchange interaction depends on the overlap of the wavefunctions which is controlled by gate voltages • At off-resonance, the wavefunction can be controlled by gate voltages as the gate pull the electron away from the nucleus: Coulomb potential is weakened → a. B increases → J-exchange overlap turns on Triplet state Singlet state NTU NEMS Laboratory