Tunable Josephson junction with added dopants
View Patent ↗A Josephson junction device includes a substrate, a base electrode layer, a top electrode layer, a tunnel barrier layer between the base electrode layer and the top electrode layer, and a dopant layer.
1 . A Josephson junction device comprising:
a substrate;
a base electrode layer;
a top electrode layer;
a tunnel barrier layer between the base electrode layer and the top electrode layer; and
a dopant layer, wherein the dopant layer is located between the base electrode layer and the substrate or is located within the top electrode layer.
2 . The Josephson junction device of claim 1 , wherein the dopant layer is located within the top electrode layer.
3 . The Josephson junction device of claim 1 , wherein the dopant layer is operative to change a response of a resistance of the Josephson junction device to heating.
4 . The Josephson junction device of claim 1 , wherein the dopant layer is made of silicon or germanium.
5 . The Josephson junction device of claim 1 , wherein the dopant layer is made of magnesium, copper, or zirconium.
6 . The Josephson junction device of claim 1 , wherein, the Josephson junction device is annealed.
7 . The Josephson junction device of claim 1 , wherein the base electrode layer has a thickness of about 20 to about 50 nanometers.
8 . The Josephson junction device of claim 1 , wherein the dopant layer has a thickness of about 1 nanometer to about 10 nanometers.
9 . The Josephson junction device of claim 1 , wherein the top electrode layer has a thickness of about 50 nanometers to about 100 nanometers.
10 . A method of fabricating a Josephson junction device, the method comprising:
forming a dopant layer over a substrate;
forming a base electrode layer over the dopant layer;
forming a tunnel barrier layer over the base electrode layer; and
forming a top electrode layer over the tunnel barrier layer.
11 . The method of claim 10 , further comprising, upon forming the top electrode layer, annealing the Josephson junction device.
12 . The method of claim 10 , wherein forming the dopant layer further comprises tuning a response of a resistance of the Josephson junction device to heating.
13 . The method of claim 10 , wherein the dopant layer is made of silicon or germanium.
14 . The method of claim 10 , wherein the dopant layer is made of magnesium, copper, or zirconium.
15 . A method of fabricating a Josephson junction device, the method comprising:
forming a base electrode layer over a substrate;
forming a tunnel barrier layer over the base electrode layer;
forming a first portion of a top electrode layer over the tunnel barrier layer;
forming a dopant layer over the first portion; and
forming a second portion of the top electrode layer over the dopant layer.
16 . The method of claim 15 , further comprising, upon forming the second portion of the top electrode layer, annealing the Josephson junction device.
17 . The method of claim 15 , wherein forming the dopant layer further comprises tuning a response of a resistance of the Josephson junction device to heating.
18 . The method of claim 15 , wherein the dopant layer is made of silicon or germanium.
19 . The method of claim 15 , wherein the dopant layer is made of magnesium, copper, or zirconium.