A Josephson junction device and methods for manufacture can include an untwinned YBa2Cu3Ox nanowire having crystallographic a- and b-axes. The nanowire can be established from YBa2Cu3Ox film (6.0≤x≤7.0) using a photolithography process, followed by an ion milling process, to yield the YBa2Cu3Ox nanowire. The crystallographic b-axis of the nanowire can be parallel to the long dimension of the nanowire. First and second gate structures can be placed on opposite sides of the nanowire across from each other, to establish first and second microgaps. A gate voltage can be selectively applied across the first and said second gate structures, which can further establish a selective electric field across the first and second microgaps. The electric field can be parallel to the nanowire crystallographic a-axis, to selectively cause an at will Josephson junction effect.