Presentation Information
[9a-S1-4]TCAD Simulation of Spin Qubits Using a GAA Transistor
〇Tetsufumi Tanamoto1, Keiji Ono2 (1.Teikyo Univ., 2.Riken)
Keywords:
GAA,Gate all-round transistor,qubit
Semiconductor spin qubits are highly compatible with existing CMOS processes and are promising for large-scale integration. However, conventional readout schemes require many dedicated electrodes and interconnects, which hinder dense qubit integration and two-dimensional array architectures. This work proposes an integrated qubit–transistor system that repurposes a gate-all-around (GAA) transistor, widely used in advanced commercial MOSFETs, as a charge-sensing readout device.
Using the Silvaco Atlas 3D device simulator, we analyzed how the qubit state influences the GAA channel current. A logical qubit is formed from two physical spin qubits, and the Pauli exclusion principle converts spin states into distinct charge distributions. Neglecting direct tunneling between the qubit and the channel, we evaluated how these spatial charge configurations modulate the nearby channel current.
When two electrons occupy separate dots (|11>L), the gate’s control of the channel is most disturbed, resulting in the strongest current suppression. When both electrons localize in a single dot (|00>L), suppression is minimal. The channel current decreases in the order |00>L → |10>L → |11>L, demonstrating that the logical qubit state can be qualitatively distinguished through the ID–VD and ID–VG characteristics of the GAA transistor.
Using the Silvaco Atlas 3D device simulator, we analyzed how the qubit state influences the GAA channel current. A logical qubit is formed from two physical spin qubits, and the Pauli exclusion principle converts spin states into distinct charge distributions. Neglecting direct tunneling between the qubit and the channel, we evaluated how these spatial charge configurations modulate the nearby channel current.
When two electrons occupy separate dots (|11>L), the gate’s control of the channel is most disturbed, resulting in the strongest current suppression. When both electrons localize in a single dot (|00>L), suppression is minimal. The channel current decreases in the order |00>L → |10>L → |11>L, demonstrating that the logical qubit state can be qualitatively distinguished through the ID–VD and ID–VG characteristics of the GAA transistor.