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The spatial wavefunction-switched field-effect transistor (SWSFET) is one of the promising quantum well devices that transfers electrons from one quantum well channel to the other channel based on the applied gate voltage. This eliminates the use of more transistors as we have coupled channels in the same device operating at different threshold voltages. This feature can be exploited in many digital integrated circuits thus reducing the count of transistors which translates to less die area. The simulations of basic sequential circuits like SR latch, D latch and flip flop are presented here using SWSFET based logic gates. The circuit model of a SWSFET was developed using Berkeley short channel IGFET model (BSIM 3).

This paper presents simulation of spatial wavefunction switched (SWS) field-effect transistors (FETs) comprising of two vertically stacked quantum dot channels. An analog behavior model (ABM) was used to compare the experimental I-V characteristics of a fabricated QD-SWS-FET. Each channel consists of two quantum dot layers and are connected to the dedicated drains D2 and D1, respectively. The fabricated SWS-FET has one source and one gate. The ABM simulation models SWS-FET comprising of two independent conventional BSIM FETs with their (W/L) ratios, capacitances and other device parameters. The agreement in simulation and experimental data will advance modeling of SWS based adders, logic gates and SRAMs.

Quantum dot gate (QDG) field-effect transistors (FETs) fabricated using Si and Ge quantum dot layers, self-assembled in the gate region over the tunnel oxide, have exhibited 3- and 4-state behavior applicable for ternary and quaternary logic, respectively. This paper presents simulation of QDG-FETs comprising mixed Ge and Si quantum dot layers over tunnel oxide using an analog behavior model (ABM) and Verilog model. The simulations reproduce the experimental I-V characteristics of a fabricated mixed dot QDG-FET. GeOx-cladded Ge quantum dot layer is in interface to the tunnel oxide and is deposited over with a SiOx-cladded Si quantum dot layer. The fabricated QDG-FET has one source and one gate. The ABM simulation models QDG-FET using conventional BSIM 3V3 FETs with capacitances and other device parameters. In addition, VERILOG model is presented. The agreement in circuit and quantum simulations and experimental data will further advance in the designing of QDG-FET-based analog-to-digital converters (ADCs), 2-bit logic gates and SRAM cells.

This paper proposes a quaternary-to-binary logic decoder, a quaternary current buffer, and a quaternary full-adder using current-mode multiple-valued logic (MVL) CMOS circuits. The proposed full-adder is superior to the previous MVL CMOS circuit in both the circuit occupied area and the performance. Comparing with the binary logic full-adder, the proposed full-adder is superior in the circuit occupied area. However, the circuit performance is inferior to the binary logic full-adder. The validity and effectiveness of the proposed circuits are verified through the HSPICE under Hynix 0.25 μm standard CMOS technology with the supply voltage 2.5 V.

The exciting properties of multi-valued logic (MVL) in overcoming the limitations of binary systems have led to widespread research on this topic. Considering various types of MVL, quaternary logic is more compatible with the existing binary systems. This paper proposes a nonvolatile quaternary flip-flop (NQFF) based on the unique features of the carbon nanotube field-effect transistors (CNTFETs) and magnetic tunnel junctions (MTJs). The proposed NQFF utilizes Spin-Hall effect (SHE)-assisted spin-transfer torque (STT) MTJs to provide nonvolatility with lower write energy, and multi-Vt gate-all-around (GAA) CNTFETs offer higher performance. On the other side, due to the usage of a shadow latch and the design of the proposed circuit, the delay of MTJ switching does not affect the delay of the whole circuit. The simulation results show that the proposed NQFF offers 50% lower PDP when the system is idle for only 25% of its total operational time.

This paper presents simulation of spatial wavefunction switched (SWS) field-effect transistors (FETs) comprising of two vertically stacked quantum dot channels. An analog behavior model (ABM) was used to compare the experimental I-V characteristics of a fabricated QD-SWS-FET. Each channel consists of two quantum dot layers and are connected to the dedicated drains D2 and D1, respectively. The fabricated SWS-FET has one source and one gate. The ABM simulation models SWS-FET comprising of two independent conventional BSIM FETs with their (W/L) ratios, capacitances and other device parameters. The agreement in simulation and experimental data will advance modeling of SWS based adders, logic gates and SRAMs.

Quantum dot gate (QDG) field-effect transistors (FETs) fabricated using Si and Ge quantum dot layers, self-assembled in the gate region over the tunnel oxide, have exhibited 3- and 4-state behavior applicable for ternary and quaternary logic, respectively. This paper presents simulation of QDG-FETs comprising mixed Ge and Si quantum dot layers over tunnel oxide using an analog behavior model (ABM) and Verilog model. The simulations reproduce the experimental I-V characteristics of a fabricated mixed dot QDG-FET. GeOx-cladded Ge quantum dot layer is in interface to the tunnel oxide and is deposited over with a SiOx-cladded Si quantum dot layer. The fabricated QDG-FET has one source and one gate. The ABM simulation models QDG-FET using conventional BSIM 3V3 FETs with capacitances and other device parameters. In addition, VERILOG model is presented. The agreement in circuit and quantum simulations and experimental data will further advance in the designing of QDG-FET-based analog-to-digital converters (ADCs), 2-bit logic gates and SRAM cells.

In order to realize the synthesis and optimization of quaternary reversible logic functions, we propose quaternary Shannon expansions generation algorithm which is based on quaternary Galois field. Combined Post algebra with Module algebra system and defined single-variable-reduced expression, obtain quaternary Galois field basic Shannon expansion by transform the quaternary function into the combination of four sub-functions which are expressed by each variables, and to get all quaternary Shannon expansions. The algorithm proposes to generate quaternary Galois field decision diagram, and apply all the expansions to express each variable of quaternary functions. The variable selection principles have ensured the SOP is optimal after flattening the decision diagram. The experiment results of some typical Benchmark functions have proved our algorithm can get SOP expressions of given functions quickly, and ensure the number of nodes and products is least.