Quantum tuning via permanent magnetic flux elements

Abstract

Systems and techniques that facilitate quantum tuning via permanent magnetic flux elements are provided. In various embodiments, a system can comprise a qubit device. In various aspects, the system can further comprise a permanent magnet having a first magnetic flux, wherein an operational frequency of the qubit device is based on the first magnetic flux. In various instances, the system can further comprise an electromagnet having a second magnetic flux that tunes the first magnetic flux. In various cases, the permanent magnet can comprise a nanoparticle magnet. In various embodiments, the nanoparticle magnet can comprise manganese nanoparticles embedded in a silicon matrix. In various aspects, the system can further comprise an electrode that applies an electric current to the nanoparticle magnet in a presence of the second magnetic flux, thereby changing a strength of the first magnetic flux.

What is claimed is: 
     
         1 . A system, comprising:
 a qubit device coupled to a first substrate; and   a permanent magnet coupled to the first substrate and emitting a first magnetic flux onto the qubit device, wherein the first magnetic flux is tuned by exposing the permanent magnet to a second magnetic flux to cause an operational frequency of the qubit device to attain a predetermined value, and wherein the permanent magnet maintains the operational frequency of the qubit device at the predetermined value upon removal of the second magnetic flux.   
     
     
         2 . The system of  claim 1 , further comprising:
 an electrode that applies an electric current to the permanent magnet while the permanent magnet is exposed to the second magnetic flux to tune the first magnetic flux.   
     
     
         3 . The system of  claim 1 , wherein tuning the first magnetic flux comprises changing a strength of the first magnetic flux to a predetermined strength corresponding to the predetermined value. 
     
     
         4 . The system of  claim 1 , further comprising:
 an electromagnet coupled to a second substrate and emitting the second magnetic flux on to the permanent magnet, wherein the first substrate is coupled to the second substrate, and wherein the first substrate and the second substrate comprise silicon or sapphire.   
     
     
         5 . The system of  claim 4 , wherein the first substrate and the second substrate are bonded back-to-back to enable external electromagnetic interaction between the permanent magnet and the electromagnet. 
     
     
         6 . The system of  claim 1 , wherein the operational frequency of the qubit device is a function of the first magnetic flux. 
     
     
         7 . The system of  claim 1 , wherein the permanent magnet is a nanoparticle magnet comprising manganese nanoparticles embedded in a silicon matrix. 
     
     
         8 . The system of  claim 1 , wherein the qubit device is a superconducting quantum interference device loop. 
     
     
         9 . A method, comprising:
 emitting, via a permanent magnet coupled to a first substrate, a first magnetic flux onto a qubit device coupled to the first substrate, wherein the first magnetic flux is tuned by exposing the permanent magnet to a second magnetic flux to cause an operational frequency of the qubit device to attain a predetermined value, and wherein the permanent magnet maintains the operational frequency of the qubit device at the predetermined value upon removal of the second magnetic flux.   
     
     
         10 . The method of  claim 9 , further comprising:
 applying, via an electrode, an electric current to the permanent magnet while the permanent magnet is exposed to the second magnetic flux to tune the first magnetic flux.   
     
     
         11 . The method of  claim 9 , wherein tuning the first magnetic flux comprises changing a strength of the first magnetic flux to a predetermined strength corresponding to the predetermined value. 
     
     
         12 . The method of  claim 9 , further comprising:
 emitting, via an electromagnet coupled to a second substrate, the second magnetic flux on to the permanent magnet, wherein the first substrate is coupled to the second substrate, and wherein the first substrate and the second substrate comprise silicon or sapphire.   
     
     
         13 . The method of  claim 12 , wherein the first substrate and the second substrate are bonded back-to-back to enable external electromagnetic interaction between the permanent magnet and the electromagnet. 
     
     
         14 . The method of  claim 9 , wherein the operational frequency of the qubit device is a function of the first magnetic flux. 
     
     
         15 . The method of  claim 9 , wherein the permanent magnet is a nanoparticle magnet comprising manganese nanoparticles embedded in a silicon matrix. 
     
     
         16 . The method of  claim 9 , wherein the qubit device is a superconducting quantum interference device loop. 
     
     
         17 . A method, comprising:
 emitting, via a permanent magnet coupled to a first substrate, a first magnetic flux onto a qubit device coupled to a second substrate, wherein the first magnetic flux is tuned by exposing the permanent magnet to a second magnetic flux to cause an operational frequency of the qubit device to attain a predetermined value, and wherein the permanent magnet maintains the operational frequency of the qubit device at the predetermined value upon removal of the second magnetic flux.   
     
     
         18 . The method of  claim 17 , further comprising:
 emitting, via an electromagnet coupled to the second substrate, the second magnetic flux on to the permanent magnet.   
     
     
         19 . The method of  claim 18 , wherein the permanent magnet and the electromagnet are fabricated in different chip-planes of the second substrate. 
     
     
         20 . The method of  claim 17 , wherein the second substrate is bonded above the first substrate using an air bridge gap, and wherein the first substrate and the second substrate comprise silicon or sapphire.