Identifying Materials-Level Sources of Performance Variation in Superconducting Transmon Qubits

  1. Akshay A. Murthy,
  2. Mustafa Bal,
  3. Michael J. Bedzyk,
  4. Hilal Cansizoglu,
  5. Randall K. Chan,
  6. Venkat Chandrasekhar,
  7. Francesco Crisa,
  8. Amlan Datta,
  9. Yanpei Deng,
  10. Celeo D. Matute Diaz,
  11. Vinayak P. Dravid,
  12. David A. Garcia-Wetten,
  13. Sabrina Garattoni,
  14. Sunil Ghimire,
  15. Dominic P. Goronzy,
  16. Sebastian de Graaf,
  17. Sam Haeuser,
  18. Mark C. Hersam,
  19. Dieter Isheim,
  20. Kamal Joshi,
  21. Richard Kim,
  22. Saagar Kolachina,
  23. Cameron J. Kopas,
  24. Matthew J. Kramer,
  25. Ella O. Lachman,
  26. Jaeyel Lee,
  27. Peter G. Lim,
  28. Andrei Lunin,
  29. William Mah,
  30. Jayss Marshall,
  31. Josh Y. Mutus,
  32. Jin-Su Oh,
  33. David Olaya,
  34. David P. Pappas,
  35. Joong-mok Park,
  36. Ruslan Prozorov,
  37. Roberto dos Reis,
  38. David N. Seidman,
  39. Zuhawn Sung,
  40. Makariy Tanatar,
  41. Mitchell J. Walker,
  42. Jigang Wang,
  43. Haotian Wu,
  44. Lin Zhou,
  45. Shaojiang Zhu,
  46. Anna Grassellino,
  47. and Alexander Romanenko
The Superconducting Materials and Systems (SQMS) Center, a DOE National Quantum Information Science Research Center, has conducted a comprehensive and coordinated study using superconducting

Disentangling the Impact of Quasiparticles and Two-Level Systems on the Statistics of Superconducting Qubit Lifetime

  1. Shaojiang Zhu,
  2. Xinyuan You,
  3. Ugur Alyanak,
  4. Mustafa Bal,
  5. Francesco Crisa,
  6. Sabrina Garattoni,
  7. Andrei Lunin,
  8. Roman Pilipenko,
  9. Akshay Murthy,
  10. Alexander Romanenko,
  11. and Anna Grassellino
Temporal fluctuations in the superconducting qubit lifetime, T1, bring up additional challenges in building a fault-tolerant quantum computer. While the exact mechanisms remain unclear,

Enhanced Superconducting Qubit Performance Through Ammonium Fluoride Etch

  1. Cameron J. Kopas,
  2. Dominic P. Goronzy,
  3. Thang Pham,
  4. Carlos G. Torres-Castanedo,
  5. Matthew Cheng,
  6. Rory Cochrane,
  7. Patrick Nast,
  8. Ella Lachman,
  9. Nikolay Z. Zhelev,
  10. Andre Vallieres,
  11. Akshay A. Murthy,
  12. Jin-su Oh,
  13. Lin Zhou,
  14. Matthew J. Kramer,
  15. Hilal Cansizoglu,
  16. Michael J. Bedzyk,
  17. Vinayak P. Dravid,
  18. Alexander Romanenko,
  19. Anna Grassellino,
  20. Josh Y. Mutus,
  21. Mark C. Hersam,
  22. and Kameshwar Yadavalli
The performance of superconducting qubits is often limited by dissipation and two-level systems (TLS) losses. The dominant sources of these losses are believed to originate from amorphous

Evaluating radiation impact on transmon qubits in above and underground facilities

  1. Francesco De Dominicis,
  2. Tanay Roy,
  3. Ambra Mariani,
  4. Mustafa Bal,
  5. Nicola Casali,
  6. Ivan Colantoni,
  7. Francesco Crisa,
  8. Angelo Cruciani,
  9. Fernando Ferroni,
  10. Dounia L Helis,
  11. Lorenzo Pagnanini,
  12. Valerio Pettinacci,
  13. Roman M Pilipenko,
  14. Stefano Pirro,
  15. Andrei Puiu,
  16. Alexander Romanenko,
  17. David v Zanten,
  18. Shaojiang Zhu,
  19. Anna Grassellino,
  20. and Laura Cardani
Superconducting qubits can be sensitive to abrupt energy deposits caused by cosmic rays and ambient radioactivity. Previous studies have focused on understanding possible correlated

Fast ZZ-Free Entangling Gates for Superconducting Qubits Assisted by a Driven Resonator

  1. Ziwen Huang,
  2. Taeyoon Kim,
  3. Tanay Roy,
  4. Yao Lu,
  5. Alexander Romanenko,
  6. Shaojiang Zhu,
  7. and Anna Grassellino
Engineering high-fidelity two-qubit gates is an indispensable step toward practical quantum computing. For superconducting quantum platforms, one important setback is the stray interaction

Systematic Improvements in Transmon Qubit Coherence Enabled by Niobium Surface Encapsulation

  1. Mustafa Bal,
  2. Akshay A. Murthy,
  3. Shaojiang Zhu,
  4. Francesco Crisa,
  5. Xinyuan You,
  6. Ziwen Huang,
  7. Tanay Roy,
  8. Jaeyel Lee,
  9. David van Zanten,
  10. Roman Pilipenko,
  11. Ivan Nekrashevich,
  12. Daniel Bafia,
  13. Yulia Krasnikova,
  14. Cameron J. Kopas,
  15. Ella O. Lachman,
  16. Duncan Miller,
  17. Josh Y. Mutus,
  18. Matthew J. Reagor,
  19. Hilal Cansizoglu,
  20. Jayss Marshall,
  21. David P. Pappas,
  22. Kim Vu,
  23. Kameshwar Yadavalli,
  24. Jin-Su Oh,
  25. Lin Zhou,
  26. Matthew J. Kramer,
  27. Dominic P. Goronzy,
  28. Carlos G. Torres-Castanedo,
  29. Graham Pritchard,
  30. Vinayak P. Dravid,
  31. James M. Rondinelli,
  32. Michael J. Bedzyk,
  33. Mark C. Hersam,
  34. John Zasadzinski,
  35. Jens Koch,
  36. James A. Sauls,
  37. Alexander Romanenko,
  38. and Anna Grassellino
We present a novel transmon qubit fabrication technique that yields systematic improvements in T1 coherence times. We fabricate devices using an encapsulation strategy that involves

Stabilizing and improving qubit coherence by engineering noise spectrum of two-level systems

  1. Xinyuan You,
  2. Ziwen Huang,
  3. Ugur Alyanak,
  4. Alexander Romanenko,
  5. Anna Grassellino,
  6. and Shaojiang Zhu
The coherence times of many widely used superconducting qubits are limited by material defects that can be modeled as an ensemble of two-level systems (TLSs). Among them, charge fluctuators

Potential Nanoscale Sources of Decoherence in Niobium based Transmon Qubit Architectures

  1. Akshay A. Murthy,
  2. Paul Masih Das,
  3. Stephanie M. Ribet,
  4. Cameron Kopas,
  5. Jaeyel Lee,
  6. Matthew J. Reagor,
  7. Lin Zhou,
  8. Matthew J. Kramer,
  9. Mark C. Hersam,
  10. Mattia Checchin,
  11. Anna Grassellino,
  12. Roberto dos Reis,
  13. Vinayak P. Dravid,
  14. and Alexander Romanenko
Superconducting thin films of niobium have been extensively employed in transmon qubit architectures. Although these architectures have demonstrated remarkable improvements in recent

TOF-SIMS Analysis of Decoherence Sources in Nb Superconducting Resonators

  1. Akshay A. Murthy,
  2. Jae-Yel Lee,
  3. Cameron Kopas,
  4. Matthew J. Reagor,
  5. Anthony P. McFadden,
  6. David P. Pappas,
  7. Mattia Checchin,
  8. Anna Grassellino,
  9. and Alexander Romanenko
Superconducting qubits have emerged as a potentially foundational platform technology for addressing complex computational problems deemed intractable with classical computing. Despite

Probing the Role of Low Temperature Vacuum Baking on Photon Lifetimes in Superconducting Niobium 3-D Resonators

  1. Daniel Bafia,
  2. Anna Grassellino,
  3. and Alexander Romanenko
We discuss a potentially dramatic source of quantum decoherence in three-dimensional niobium superconducting resonators and in two-dimensional transmon qubits that utilize oxidized