Standard Error Amplification circuit

doc/source/protocols/index.rst

@@ -46,4 +46,5 @@ In this section we introduce the basics of all protocols supported by ``qibocal`
     chsh
     twpa_calibration/twpa
     cross_resonance/cross_resonance
+    standard_error_amplification
     references

doc/source/protocols/standard_error_amplification.rst

@@ -0,0 +1,64 @@
+.. _standard_error_amplification:
+
+Standard Error Amplification
+============================
+
+The goal of the Standard Error Amplification experiment is to estimate the error on the conditional phase acquired by the :math:`CZ` gate.
+
+An ideal :math:`CZ` gate applies a phase of :math:`\pi` to the :math:`\ket{11}` component of the two-qubit state and leaves the other computational states unchanged.
+In practice, the gate implemented on hardware applies a phase :math:`\pi + \delta`, where :math:`\delta` is a small, unknown error.
+
+The implementation of the protocol follows the one described in :cite:p:`sea`.
+
+Standard Error Amplification
+-----------------------------
+
+Let :math:`Q_a` be the probe qubit and :math:`Q_b` the control qubit of the pair.
+
+The experiment consists of the following circuit:
+
+..
+  missing svg image of the circuit
+
+The net phase accumulated by :math:`Q_a` after the full sequence is, up to known and calculable offsets,
+
+.. math:: \phi_n = n\,\delta .
+    :label: sea_phase
+
+The final :math:`X(\pi/2)` pulse on :math:`Q_a` is the same rotation as the initial one: it converts the phase :math:`\phi_n` of :eq:`sea_phase` into a measurable excited-state population
+
+.. math:: P(\ket{1}_{Q_a}) \approx \cos^2\left(\frac{n\,\delta}{2}\right)
+    :label: sea_population
+
+By measuring :math:`P(\ket{1}_{Q_a})` as a function of the number of repetitions :math:`n` and fitting it to a sinusoid, it is possible to extract :math:`\delta`.
+
+Parameters
+^^^^^^^^^^
+
+.. autoclass::
+	qibocal.protocols.two_qubit_interaction.sea.StandardErrorAmplificationParameters
+	:noindex:
+
+Example
+^^^^^^^
+It follows a runcard example of this experiment.
+
+.. code-block:: yaml
+
+    - id: standard_error_amplification
+      operation: standard_error_amplification
+      targets: [[0, 1]]
+      parameters:
+        nshots: 2000
+        repetitions_max: 10
+        repetitions_step: 1
+
+The expected output is the following:
+
+.. image::
+
+
+Requirements
+^^^^^^^^^^^^
+
+- :ref:`cz_amplitude`

doc/source/refs.bib

@@ -213,157 +213,171 @@ @article{Cryoscope_20
 }
 
 @article{Motzoi_2009,
-   title={Simple Pulses for Elimination of Leakage in Weakly Nonlinear Qubits},
-   volume={103},
-   ISSN={1079-7114},
-   url={http://dx.doi.org/10.1103/PhysRevLett.103.110501},
-   DOI={10.1103/physrevlett.103.110501},
-   number={11},
-   journal={Physical Review Letters},
-   publisher={American Physical Society (APS)},
-   author={Motzoi, F. and Gambetta, J. M. and Rebentrost, P. and Wilhelm, F. K.},
-   year={2009},
-   month=sep }
+  title     = {Simple Pulses for Elimination of Leakage in Weakly Nonlinear Qubits},
+  volume    = {103},
+  issn      = {1079-7114},
+  url       = {http://dx.doi.org/10.1103/PhysRevLett.103.110501},
+  doi       = {10.1103/physrevlett.103.110501},
+  number    = {11},
+  journal   = {Physical Review Letters},
+  publisher = {American Physical Society (APS)},
+  author    = {Motzoi, F. and Gambetta, J. M. and Rebentrost, P. and Wilhelm, F. K.},
+  year      = {2009},
+  month     = sep
+}
 
 
 @article{Gambetta_2011,
-   title={Analytic control methods for high-fidelity unitary operations in a weakly nonlinear oscillator},
-   volume={83},
-   ISSN={1094-1622},
-   url={http://dx.doi.org/10.1103/PhysRevA.83.012308},
-   DOI={10.1103/physreva.83.012308},
-   number={1},
-   journal={Physical Review A},
-   publisher={American Physical Society (APS)},
-   author={Gambetta, J. M. and Motzoi, F. and Merkel, S. T. and Wilhelm, F. K.},
-   year={2011},
-   month=jan }
+  title     = {Analytic control methods for high-fidelity unitary operations in a weakly nonlinear oscillator},
+  volume    = {83},
+  issn      = {1094-1622},
+  url       = {http://dx.doi.org/10.1103/PhysRevA.83.012308},
+  doi       = {10.1103/physreva.83.012308},
+  number    = {1},
+  journal   = {Physical Review A},
+  publisher = {American Physical Society (APS)},
+  author    = {Gambetta, J. M. and Motzoi, F. and Merkel, S. T. and Wilhelm, F. K.},
+  year      = {2011},
+  month     = jan
+}
 
 @article{Sheldon_2016,
-   title={Characterizing errors on qubit operations via iterative randomized benchmarking},
-   volume={93},
-   ISSN={2469-9934},
-   url={http://dx.doi.org/10.1103/PhysRevA.93.012301},
-   DOI={10.1103/physreva.93.012301},
-   number={1},
-   journal={Physical Review A},
-   publisher={American Physical Society (APS)},
-   author={Sheldon, Sarah and Bishop, Lev S. and Magesan, Easwar and Filipp, Stefan and Chow, Jerry M. and Gambetta, Jay M.},
-   year={2016},
-   month=jan }
+  title     = {Characterizing errors on qubit operations via iterative randomized benchmarking},
+  volume    = {93},
+  issn      = {2469-9934},
+  url       = {http://dx.doi.org/10.1103/PhysRevA.93.012301},
+  doi       = {10.1103/physreva.93.012301},
+  number    = {1},
+  journal   = {Physical Review A},
+  publisher = {American Physical Society (APS)},
+  author    = {Sheldon, Sarah and Bishop, Lev S. and Magesan, Easwar and Filipp, Stefan and Chow, Jerry M. and Gambetta, Jay M.},
+  year      = {2016},
+  month     = jan
+}
 
 @misc{reed2013entanglementquantumerrorcorrection,
-      title={Entanglement and Quantum Error Correction with Superconducting Qubits},
-      author={Matthew Reed},
-      year={2013},
-      eprint={1311.6759},
-      archivePrefix={arXiv},
-      primaryClass={quant-ph},
-      url={https://arxiv.org/abs/1311.6759},
+  title         = {Entanglement and Quantum Error Correction with Superconducting Qubits},
+  author        = {Matthew Reed},
+  year          = {2013},
+  eprint        = {1311.6759},
+  archiveprefix = {arXiv},
+  primaryclass  = {quant-ph},
+  url           = {https://arxiv.org/abs/1311.6759}
 }
 
 @article{Klimov_2018,
-   title={Fluctuations of Energy-Relaxation Times in Superconducting Qubits},
-   volume={121},
-   ISSN={1079-7114},
-   url={http://dx.doi.org/10.1103/PhysRevLett.121.090502},
-   DOI={10.1103/physrevlett.121.090502},
-   number={9},
-   journal={Physical Review Letters},
-   publisher={American Physical Society (APS)},
-   author={Klimov, P. V. and Kelly, J. and Chen, Z. and Neeley, M. and Megrant, A. and Burkett, B. and Barends, R. and Arya, K. and Chiaro, B. and Chen, Yu and Dunsworth, A. and Fowler, A. and Foxen, B. and Gidney, C. and Giustina, M. and Graff, R. and Huang, T. and Jeffrey, E. and Lucero, Erik and Mutus, J. Y. and Naaman, O. and Neill, C. and Quintana, C. and Roushan, P. and Sank, Daniel and Vainsencher, A. and Wenner, J. and White, T. C. and Boixo, S. and Babbush, R. and Smelyanskiy, V. N. and Neven, H. and Martinis, John M.},
-   year={2018},
-   month=aug }
+  title     = {Fluctuations of Energy-Relaxation Times in Superconducting Qubits},
+  volume    = {121},
+  issn      = {1079-7114},
+  url       = {http://dx.doi.org/10.1103/PhysRevLett.121.090502},
+  doi       = {10.1103/physrevlett.121.090502},
+  number    = {9},
+  journal   = {Physical Review Letters},
+  publisher = {American Physical Society (APS)},
+  author    = {Klimov, P. V. and Kelly, J. and Chen, Z. and Neeley, M. and Megrant, A. and Burkett, B. and Barends, R. and Arya, K. and Chiaro, B. and Chen, Yu and Dunsworth, A. and Fowler, A. and Foxen, B. and Gidney, C. and Giustina, M. and Graff, R. and Huang, T. and Jeffrey, E. and Lucero, Erik and Mutus, J. Y. and Naaman, O. and Neill, C. and Quintana, C. and Roushan, P. and Sank, Daniel and Vainsencher, A. and Wenner, J. and White, T. C. and Boixo, S. and Babbush, R. and Smelyanskiy, V. N. and Neven, H. and Martinis, John M.},
+  year      = {2018},
+  month     = aug
+}
 
 @misc{pasquale2024qibocalopensourceframeworkcalibration,
-      title={Qibocal: an open-source framework for calibration of self-hosted quantum devices},
-      author={Andrea Pasquale and Edoardo Pedicillo and Juan Cereijo and Sergi Ramos-Calderer and Alessandro Candido and Gabriele Palazzo and Rodolfo Carobene and Marco Gobbo and Stavros Efthymiou and Yuanzheng Paul Tan and Ingo Roth and Matteo Robbiati and Jadwiga Wilkens and Alvaro Orgaz-Fuertes and David Fuentes-Ruiz and Andrea Giachero and Frederico Brito and José Ignacio Latorre and Stefano Carrazza},
-      year={2024},
-      eprint={2410.00101},
-      archivePrefix={arXiv},
-      primaryClass={quant-ph},
-      url={https://arxiv.org/abs/2410.00101},
+  title         = {Qibocal: an open-source framework for calibration of self-hosted quantum devices},
+  author        = {Andrea Pasquale and Edoardo Pedicillo and Juan Cereijo and Sergi Ramos-Calderer and Alessandro Candido and Gabriele Palazzo and Rodolfo Carobene and Marco Gobbo and Stavros Efthymiou and Yuanzheng Paul Tan and Ingo Roth and Matteo Robbiati and Jadwiga Wilkens and Alvaro Orgaz-Fuertes and David Fuentes-Ruiz and Andrea Giachero and Frederico Brito and José Ignacio Latorre and Stefano Carrazza},
+  year          = {2024},
+  eprint        = {2410.00101},
+  archiveprefix = {arXiv},
+  primaryclass  = {quant-ph},
+  url           = {https://arxiv.org/abs/2410.00101}
 }
 
 @misc{shin2024inoperandomicrowavescatteringparametercalibrated,
-      title={In-operando microwave scattering-parameter calibrated measurement of a Josephson travelling wave parametric amplifier},
-      author={S. H. Shin and M. Stanley and W. N. Wong and T. Sweetnam and A. Elarabi and T. Lindström and N. M. Ridler and S. E. de Graaf},
-      year={2024},
-      eprint={2406.03063},
-      archivePrefix={arXiv},
-      primaryClass={quant-ph},
-      url={https://arxiv.org/abs/2406.03063},
+  title         = {In-operando microwave scattering-parameter calibrated measurement of a Josephson travelling wave parametric amplifier},
+  author        = {S. H. Shin and M. Stanley and W. N. Wong and T. Sweetnam and A. Elarabi and T. Lindström and N. M. Ridler and S. E. de Graaf},
+  year          = {2024},
+  eprint        = {2406.03063},
+  archiveprefix = {arXiv},
+  primaryclass  = {quant-ph},
+  url           = {https://arxiv.org/abs/2406.03063}
 }
 
 @article{CR_First,
-  title = {Microwave-induced coupling of superconducting qubits},
-  author = {Paraoanu, G. S.},
-  journal = {Phys. Rev. B},
-  volume = {74},
-  issue = {14},
-  pages = {140504},
-  numpages = {4},
-  year = {2006},
-  month = {Oct},
+  title     = {Microwave-induced coupling of superconducting qubits},
+  author    = {Paraoanu, G. S.},
+  journal   = {Phys. Rev. B},
+  volume    = {74},
+  issue     = {14},
+  pages     = {140504},
+  numpages  = {4},
+  year      = {2006},
+  month     = {Oct},
   publisher = {American Physical Society},
-  doi = {10.1103/PhysRevB.74.140504},
-  url = {https://link.aps.org/doi/10.1103/PhysRevB.74.140504}
+  doi       = {10.1103/PhysRevB.74.140504},
+  url       = {https://link.aps.org/doi/10.1103/PhysRevB.74.140504}
 }
 
 @article{CR_Righetti,
-  title = {Fully microwave-tunable universal gates in superconducting qubits with linear couplings and fixed transition frequencies},
-  author = {Rigetti, Chad and Devoret, Michel},
-  journal = {Phys. Rev. B},
-  volume = {81},
-  issue = {13},
-  pages = {134507},
-  numpages = {7},
-  year = {2010},
-  month = {Apr},
+  title     = {Fully microwave-tunable universal gates in superconducting qubits with linear couplings and fixed transition frequencies},
+  author    = {Rigetti, Chad and Devoret, Michel},
+  journal   = {Phys. Rev. B},
+  volume    = {81},
+  issue     = {13},
+  pages     = {134507},
+  numpages  = {7},
+  year      = {2010},
+  month     = {Apr},
   publisher = {American Physical Society},
-  doi = {10.1103/PhysRevB.81.134507},
-  url = {https://link.aps.org/doi/10.1103/PhysRevB.81.134507}
+  doi       = {10.1103/PhysRevB.81.134507},
+  url       = {https://link.aps.org/doi/10.1103/PhysRevB.81.134507}
 }
 
 @article{CR_Second,
-author = {Groot, P. and Lisenfeld, Jürgen and Schouten, R. and Ashhab, S. and Lupascu, Adrian and Harmans, Kees and Mooij, Hans},
-year = {2010},
-month = {08},
-pages = {},
-title = {Selective darkening of degenerate transitions demonstrated with two
-superconducting quantum bits},
-volume = {6},
-journal = {Nature Physics},
-doi = {10.1038/nphys1733}
+  author  = {Groot, P. and Lisenfeld, Jürgen and Schouten, R. and Ashhab, S. and Lupascu, Adrian and Harmans, Kees and Mooij, Hans},
+  year    = {2010},
+  month   = {08},
+  pages   = {},
+  title   = {Selective darkening of degenerate transitions demonstrated with two
+             superconducting quantum bits},
+  volume  = {6},
+  journal = {Nature Physics},
+  doi     = {10.1038/nphys1733}
 }
 
 @book{Manenti:2023zzn,
-    author = "Manenti, Riccardo and Motta, Mario",
-    title = "{Quantum Information Science}",
-    isbn = "978-0-19-878748-8",
-    publisher = "Oxford University Press",
-    month = "8",
-    year = "2023"
+  author    = {Manenti, Riccardo and Motta, Mario},
+  title     = {{Quantum Information Science}},
+  isbn      = {978-0-19-878748-8},
+  publisher = {Oxford University Press},
+  month     = {8},
+  year      = {2023}
 }
 
 @article{CRDrag,
-author = {Li, Boxi and Calarco, Tommaso and Motzoi, Felix},
-year = {2024},
-month = {07},
-pages = {},
-title = {Experimental error suppression in Cross-Resonance gates via multi-derivative pulse shaping},
-volume = {10},
-journal = {npj Quantum Information},
-doi = {10.1038/s41534-024-00863-4}
+  author  = {Li, Boxi and Calarco, Tommaso and Motzoi, Felix},
+  year    = {2024},
+  month   = {07},
+  pages   = {},
+  title   = {Experimental error suppression in Cross-Resonance gates via multi-derivative pulse shaping},
+  volume  = {10},
+  journal = {npj Quantum Information},
+  doi     = {10.1038/s41534-024-00863-4}
 }
 
 @article{CR_IBM,
-  title={Procedure for systematically tuning up cross-talk in the cross-resonance gate},
-  author={Sheldon, Sarah and Magesan, Easwar and Chow, Jerry M and Gambetta, Jay M},
-  journal={Physical Review A},
-  volume={93},
-  number={6},
-  pages={060302},
-  year={2016},
-  publisher={APS}
+  title     = {Procedure for systematically tuning up cross-talk in the cross-resonance gate},
+  author    = {Sheldon, Sarah and Magesan, Easwar and Chow, Jerry M and Gambetta, Jay M},
+  journal   = {Physical Review A},
+  volume    = {93},
+  number    = {6},
+  pages     = {060302},
+  year      = {2016},
+  publisher = {APS}
+}
+
+@misc{sea,
+  title         = {High-Precision Calibration Workflow Achieves Above $99.9\%$ CZ Gate Fidelity on a Scalable Superconducting Processor},
+  author        = {Huili Zhang and Meiling Li and Shuang Yang and Yaqing Feng and Yulong Li and Cheng Chen and Pei Liu and Guangming Xue and Haifeng Yu},
+  year          = {2026},
+  eprint        = {2607.01422},
+  archiveprefix = {arXiv},
+  primaryclass  = {quant-ph},
+  url           = {https://arxiv.org/abs/2607.01422}
 }

src/qibocal/calibration/calibration.py

@@ -150,6 +150,8 @@ class TwoQubitCalibration(Model):
     """CZ interleaved rb fidelity."""
     coupling: list[float] | None = None
     """Qubit-qubit coupling."""
+    conditional_phase: list[float] | None = None
+    """Accumulated conditional phase of the gate."""
 
 
 class Calibration(Model):

src/qibocal/protocols/two_qubit_interaction/__init__.py

@@ -7,6 +7,7 @@
     cr_length,
 )
 from .optimize import optimize_two_qubit_gate
+from .sea import standard_error_amplification
 from .snz_optimize import snz_optimize
 from .snz_optimize_t_idle import snz_optimize_t_idle
 from .snz_optimize_t_idle_vs_t_tot import snz_optimize_t_idle_vs_t_tot
@@ -25,4 +26,5 @@
     "snz_optimize",
     "snz_optimize_t_idle",
     "snz_optimize_t_idle_vs_t_tot",
+    "standard_error_amplification",
 ]