Cross capacitances with 1D traces BSc/MSc Project: Cross capacitances with 1D traces Single spins trapped in a quantum dot can be used as quantum bits (qubits) in a quantum computer. The basic components, initialization, manipulation, and read-out are demonstrated in multiple quantum dot systems [Rev. Mod. Phys. 79, 1217 (2007)]. When scaling up these systems, automated tuning and operation becomes important. Gate defined GaAs quantum dots A promising platform for testing quantum protocols is provided by electron spins captured in a solid state semiconductor. Architectures of gate defined quantum dots have been well established for GaAs based heterostructures. Recently the first steps in automated tuning of spin qubits have been demonstrated [arxiv.org/abs/1603.02274]. Figure 1: Electron micrograph picture of a quantum dot device. Quantum dots are formed by voltages applied on the electrodes. Specific lines are connected to high frequency sources to enable manipulation and shuttling of single spins. 1D traces An important source of information are the 2D charge stability diagrams (i.e. honeycombs). In order to obtain information faster and some technical reasons we want to extract information such as capacitive couplings from 1D scans (traces). In this BSc work you will create algorithms to automatically determine cross-capacitances using only 1D scans. The data from the scans will be fitted to a physical model of a charge transition or polarization line. The work will be integrated in the toolbox developed a the spin qubit group. Figure 2: Charge stability diagram of a double quantum dot. The lines correspond to electrons being added or removed to the left or right dot of the system Skills you will acquire: Seeing quantum mechanics at work in the lab Fitting measurement data to physical models Software engineering Sharing your ideas in a stimulating scientific environment We are looking for a student that is up for this challenging project. Interested? Please contact: Pieter Eendebak (supervisor): pieter.eendebak@tno.nl Lieven Vandersypen (group leader): L.M.K.Vandersypen@tudelft.nll Spin qubit homepage: http://vandersypenlab.tudelft.nl/