Control on the Sensor Coherence of Transmon Superconducting Qubit via the Gradient Descent Algorithm


Borisenok S.

International Journal of Advanced Natural Sciences and Engineering Researches, vol.7, no.11, pp.278-282, 2023 (Peer-Reviewed Journal)

  • Publication Type: Article / Article
  • Volume: 7 Issue: 11
  • Publication Date: 2023
  • Doi Number: 10.59287/as-ijanser.628
  • Journal Name: International Journal of Advanced Natural Sciences and Engineering Researches
  • Page Numbers: pp.278-282
  • Abdullah Gül University Affiliated: Yes

Abstract

Quantum systems based on superconducting circuits with qubits with quantized energy levels serve  as  an  efficient  physical  background  for constructing  different  quantum  devices,  for  instance, quantum sensors. The important class of such engineering devices belongs to the systems with quantum tunneling  effects,  like  Josephson  junctions,  where  the  set  of  energy  levels  is  influenced  by  the  external fields.  These  fields  change  the  phase  properties  of  the  measuring  qubits,  and,  in  this  way,  they  can  be detected.  The  weakly  anharmonic  oscillator  is  often  referred  as  a  transmon  qubit.  Such  qubits  are constructed  with  superconducting  capacitor  structures  connected  by  Josephson  junctions,  they  can  be controlled by microwave pulses of a  few nanoseconds.The quantum sensing mechanism studied here is based on coupling the measuring transmon superconducting qubits with magnetic materials. The sensing protocol  of  Ramsey  Fringes  interferometry  covers  several  stages  and  demands high-quality  control  over the  sensor  coherence.  Although  the  weakly  nonlinear  properties  of  transmons  prevent  the  sensing procedure  from  the  strong  influence  of  external  perturbations,  nevertheless,  the  extension  of  the coherence time interval and minimization of the dephasing effects are still a matter of great importance. Here  we  discuss  the  improvement  of  the  quantum  sensor  performance  by  the  application  of  feedback control in the form of gradient descent algorithm over the dephasing factor-function.  Keywords –Quantum Sensors, Transmon Superconducting Qubit, Sensor Coherence, Dephasing, Gradient Descent Algorithm