A Design and Application Case Study of Binary Semaphore Using 2 Dimensional 2 Dot 1 Electron Quantum Dot Cellular Automata Sunanda Mondal 1(B ) , Mili Ghosh 1 , Kakali Datta 1 , Debarka Mukhopadhyay 2 , and Paramartha Dutta 1 1 Department of Computer and System Sciences, Visva Bharati University, Santiniketan, India sund.mondal@gmail.com, ghosh.mili90@gmail.com, kakali.datta@gmail.com, paramartha.dutta@gmail.com 2 Department of Computer Science, Amity School of Engineering and Technology, Amity University, Kolkata, India debarka.mukhopadhyay@gmail.com Abstract. Quantum-dot Cellular Automata (QCA) appeared as a com- prehensive solution to the shortfalls CMOS technology is facing in case of nanoscale implementations. This emerging nanotechnological paradigm promises high speed, energy eﬃcient computing. In this present scope, the concept of binary semaphore has been implemented using J- K Flipﬂop with the 4-dot 2-electron variant of Quantum-dot Cellular Automata. Later we analyze the proposed layout with respect to suit- able well established metrics. In addition we provide a case study of the proposed semaphore layout on traﬃc control system which comes out to oﬀer a way more optimized in respect of power utilization. Keywords: 4-dot 2-electron QCA · Coulomb’s law · Majority voter Semaphore · Binary semaphore · J-K ﬂipﬂop 1 Introduction Eﬃcient solution to technological limitations of existing technologies (Sem (2012)) in nanoscale encourages researchers to ﬁnd out eﬃcient alternatives. Quantum-dot Cellular Automata (QCA) was ﬁrst proposed by Lent and Tougaw in Lent and Tougaw (1997). QCA ensures edge-driven ﬂow of data and energy, information processing near the ground state, high density, high energy eﬃciency and ultra fast computation speed (Lent and Tougaw (1997)). The most researched counterpart of QCA is the 4 Dot 2 Electron version (Farazkish et al. (2008); Oya et al. (2003)). The designs of some well known logic constructs such as MUX, adders, ﬂipﬂops have been reported in Mukhopadhyay et al. (2011); Mukhopadhyay and Dutta (2012b); Navi et al. (2010); Dutta and c  Springer Nature Singapore Pte Ltd. 2018 J. K. Mandal and D. Sinha (Eds.): CSI 2017, CCIS 836, pp. 428–448, 2018. https://doi.org/10.1007/978-981-13-1343-1_36