Twisted track interferometer for producing magic states
View Patent ↗A twisted track interferometer (TTI) for producing magic states is disclosed. The spin of ½-vortices may be exploited to produce magic states. The disclosed “twisted track interferometer” is a “topological twist” on the conventional Pabre-Pero interferometer adapted to topological superconductors. In the disclosed TTI, the probe particles may be Josephson vortices (JVs). JVs are estimated to be light and will tunnel more easily than Abrikosov vortices. Also, the disclosed TTI does not require multiple tunneling events. Rather, the JVs are propelled down thin insulating tracks within a 2D topological p-wave superconductor by a Magnus force generated by a tunneling supercurrent across the tracks. The JVs encounter tunneling junctions as they pass into the arms of the TTI.
1. A twisted track interferometer, comprising:
a two-dimensional topological superconductor having a superconductivity, with first and second tracks that are formed as insulating defects in the superconductivity of the topological superconductor, wherein probe anyons are provided to the first and second tracks, the first track having at least one twisted portion, and the second track having a length sufficient to allow for the probe anyons to traverse the first track;
a qubit encoded in four anyons, the qubit having an initial state, and
a flux measuring device that determines a final state of the qubit after the probe anyons traverse the first and second tracks.
2. The twisted track interferometer of claim 1 , wherein the probe anyons are physically spun sufficiently to change a state of the qubit between |1 and |Ψ .
3. The twisted track interferometer of claim 2 , wherein the twisted portion includes first and second loops in the first track, and wherein the probe anyons are physically spun 360° in each of the two loops for a total spin of 720°.
4. The twisted track interferometer of claim 1 , wherein the probe anyons are Josephson vortices.
5. The twisted track interferometer of claim 1 , wherein the probe anyons are physical realizations of Ising anyons in the topological superconductor.
6. The twisted track interferometer of claim 1 , wherein the probe anyons are provided to the first and second tracks from a Josephson Vortex storage ring.
7. The twisted track interferometer of claim 1 , further comprising an entry track that separates the probe anyons from high-energy events needed to enter the probe anyons onto the entry track.
8. The twisted track interferometer of claim 1 , wherein the probe anyons do not spin as they traverse the second track.
9. The twisted track interferometer of claim 1 , further comprising a pair of parallel tracks that are close enough to one another for interactions between probe anyons to exist, wherein slow and fast regions are alternatingly arranged in each of the parallel tracks, wherein the slow and fast regions are formed from variations in a material structure of the tracks.
10. The twisted track interferometer of claim 1 , wherein the twisted track interferometer enables topologically protected production of magic states in a topological quantum computer based on two-dimensional topological superconductors.
11. The twisted track interferometer of claim 1 , wherein the twisted track interferometer enables construction of a universal gate set for quantum computation on a topological superconductor substrate.
12. A Josephson Vortex (JV) storage ring, the JV storage ring comprising:
circular track formed as an insulating defect in the superconductivity of a topological superconductor, the circular track having a tunneling barrier; and
a pair of electrostatic top gates that simultaneously break the circular track and lower the tunneling barrier.
13. The JV storage ring of claim 11 , wherein Josephson Vortices (JVs) are introduced into a circular track by a flux solenoid.
14. The JV storage ring of claim 12 , wherein an internal/external phase differential Φ 1 >Φ 0 keeps JVs in circulation in the circular track.
15. The JV storage ring of claim 11 , wherein the electrostatic top gates lower the tunneling barrier to a second track that is separated from the circular track.
16. The JV storage ring of claim 15 , wherein the second track leads to an interferometric system.
17. The JV storage ring of claim 15 , wherein the electrostatic top gates are controlled by gate pulses having frequency components of at least one gigahertz.
18. A method for producing magic states in a quantum computational system, the method comprising:
forming first and second pairs of tracks in a topological chiral superconductor, the superconductor having superconductivity, each of the tracks corresponding to a respective weakness in the superconductivity of the superconductor, wherein the first pair of tracks is contoured to form two twisting loops, and the second pair of tracks is contoured to provide a delay;
pairing ±Josephson Vortices (JVs) into excitons;
sending the excitons down the pairs of tracks; and
counting flux loops that bind a selected two of the tracks.
19. The method of claim 18 , wherein interactions between the excitons are dipolar.
20. The method of claim 19 , wherein oppositely oriented pairs of JVs are paired into magnetic field loops that interact as dipoles.