Akito Suzuki Yohei Tanaka The Witten index for 1D supersymmetric quantum walks with anisotropic coins. 377 2019 18 Quantum Inf. Process. 12 https://doi.org/10.1007/s11128-019-2485-1 https://www.wikidata.org/entity/Q126830789 db/journals/qip/qip18.html#SuzukiT19