- Letter
- Open Access
Global variational quantum circuits for arbitrary symmetric state preparation
Phys. Rev. Research 7, L022072 – Published 20 June, 2025
DOI: https://doi.org/10.1103/PhysRevResearch.7.L022072
Abstract
Quantum states that are symmetric under particle exchange play a crucial role in fields such as quantum metrology and quantum error correction. We use a variational circuit composed of global one-axis twisting and global rotations to efficiently prepare arbitrary symmetric states, i.e., any superposition of Dicke states. The circuit does not require local addressability or ancilla qubits and thus can be readily implemented in a variety of experimental platforms including trapped-ion quantum simulators and cavity QED systems. We provide analytic and numerical evidence that any -qubit symmetric state can be prepared in steps. We demonstrate the utility of our protocol by preparing (i) metrologically useful -qubit Dicke states of up to qubits in gate steps with theoretical infidelities , (ii) the Ruskai codewords in gate steps with , and (iii) the Gross codewords in gate steps with . Focusing on trapped-ion platforms, for the Ruskai and Gross codewords we estimate that the protocol achieves fidelities in the presence of typical experimental noise levels, thus providing a pathway to the preparation of a wide range of useful highly entangled quantum states.
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References (73)
- D. Bluvstein, S. J. Evered, A. A. Geim, S. H. Li, H. Zhou, T. Manovitz, S. Ebadi, M. Cain, M. Kalinowski, D. Hangleiter, J. P. B. Ataides, N. Maskara, I. Cong, X. Gao, P. S. Rodriguez, T. Karolyshyn, G. Semeghini, M. J. Gullans, M. Greiner, V. Vuletić et al., Logical quantum processor based on reconfigurable atom arrays, Nature (London) 626, 58 (2023).
- S. Krinner, N. Lacroix, A. Remm, A. Di Paolo, E. Genois, C. Leroux, C. Hellings, S. Lazar, F. Swiadek, J. Herrmann, G. J. Norris, C. K. Andersen, M. Müller, A. Blais, C. Eichler, and A. Wallraff, Realizing repeated quantum error correction in a distance-three surface code, Nature (London) 605, 669 (2022).
- V. V. Sivak, A. Eickbusch, B. Royer, S. Singh, I. Tsioutsios, S. Ganjam, A. Miano, B. L. Brock, A. Z. Ding, L. Frunzio, S. M. Girvin, R. J. Schoelkopf, and M. H. Devoret, Real-time quantum error correction beyond break-even, Nature (London) 616, 50 (2023).
- B. M. Terhal, Quantum error correction for quantum memories, Rev. Mod. Phys. 87, 307 (2015).
- Y. Ouyang, Permutation-invariant quantum codes, Phys. Rev. A 90, 062317 (2014).
- M. B. Ruskai, Pauli exchange errors in quantum computation, Phys. Rev. Lett. 85, 194 (2000).
- J. A. Gross, Designing codes around interactions: The case of a spin, Phys. Rev. Lett. 127, 010504 (2021).
- G. Tóth, Multipartite entanglement and high-precision metrology, Phys. Rev. A 85, 022322 (2012).
- Y. Ouyang and G. K. Brennen, Finite-round quantum error correction on symmetric quantum sensors, arXiv:2212.06285.
- M. Plesch and V. Bužek, Efficient compression of quantum information, Phys. Rev. A 81, 032317 (2010).
- D. Bacon, I. L. Chuang, and A. W. Harrow, Efficient quantum circuits for schur and clebsch-gordan transforms, Phys. Rev. Lett. 97, 170502 (2006).
- R. Prevedel, G. Cronenberg, M. S. Tame, M. Paternostro, P. Walther, M. S. Kim, and A. Zeilinger, Experimental realization of dicke states of up to six qubits for multiparty quantum networking, Phys. Rev. Lett. 103, 020503 (2009).
- A. Bärtschi and S. Eidenbenz, Short-depth circuits for dicke state preparation, in 2022 IEEE International Conference on Quantum Computing and Engineering (QCE) (2022), pp. 87–96.
- S. Aktar, A. Bärtschi, A.-H. A. Badawy, and S. Eidenbenz, A divide-and-conquer approach to dicke state preparation, Trans. Quantum Eng. 3, 1 (2022).
- H. Buhrman, M. Folkertsma, B. Loff, and N. M. P. Neumann, State preparation by shallow circuits using feed forward, Quantum 8, 1552 (2024).
- For example, the four symmetric Dicke states are and .
- H. J. Briegel and R. Raussendorf, Persistent entanglement in arrays of interacting particles, Phys. Rev. Lett. 86, 910 (2001).
- X. Wang and K. Mølmer, Pairwise entanglement in symmetric multi-qubit systems, Eur. Phys, J. D. At. Mol. Opt. Phys. 18, 385 (2002).
- J. K. Stockton, J. M. Geremia, A. C. Doherty, and H. Mabuchi, Characterizing the entanglement of symmetric many-particle spin- 1/2 systems, Phys. Rev. A 67, 022112 (2003).
- A. Neven, J. Martin, and T. Bastin, Entanglement robustness against particle loss in multiqubit systems, Phys. Rev. A 98, 062335 (2018).
- D. J. Wineland, J. J. Bollinger, W. M. Itano, and D. Heinzen, Squeezed atomic states and projection noise in spectroscopy, Phys. Rev. A 50, 67 (1994).
- L. Pezzè, A. Smerzi, M. K. Oberthaler, R. Schmied, and P. Treutlein, Quantum metrology with nonclassical states of atomic ensembles, Rev. Mod. Phys. 90, 035005 (2018).
- M. Koashi, V. Bužek, and N. Imoto, Entangled webs: Tight bound for symmetric sharing of entanglement, Phys. Rev. A 62, 050302(R) (2000).
- W. Dür, G. Vidal, and J. I. Cirac, Three qubits can be entangled in two inequivalent ways, Phys. Rev. A 62, 062314 (2000).
- M. T. Johnsson, N. R. Mukty, D. Burgarth, T. Volz, and G. K. Brennen, Geometric pathway to scalable quantum sensing, Phys. Rev. Lett. 125, 190403 (2020).
- S. S. Ivanov, N. V. Vitanov, and N. V. Korolkova, Creation of arbitrary dicke and noon states of trapped-ion qubits by global addressing with composite pulses, New J. Phys. 15, 023039 (2013).
- V. M. Stojanovic and J. K. Nauth, Dicke-state preparation through global transverse control of Ising-coupled qubits, Phys. Rev. A 108, 012608 (2023).
- D. B. Hume, C. W. Chou, T. Rosenband, and D. J. Wineland, Preparation of dicke states in an ion chain, Phys. Rev. A 80, 052302 (2009).
- C. Wu, C. Guo, Y. Wang, G. Wang, X.-L. Feng, and J.-L. Chen, Generation of dicke states in the ultrastrong-coupling regime of circuit qed systems, Phys. Rev. A 95, 013845 (2017).
- K. D. B. Higgins, S. C. Benjamin, T. M. Stace, G. J. Milburn, B. W. Lovett, and E. M. Gauger, Superabsorption of light via quantum engineering, Nat. Commun. 5, 4705 (2014).
- Y. Zhao, R. Zhang, W. Chen, X.-B. Wang, and J. Hu, Creation of Greenberger-Horne-Zeilinger states with thousands of atoms by entanglement amplification, npj Quantum Inf. 7, 24 (2021).
- D. M. Greenberger, M. A. Horne, and A. Zeilinger, Going beyond bell's theorem, in Bell's Theorem, Quantum Theory and Conceptions of the Universe, edited by M. Kafatos (Springer Netherlands, Dordrecht, 1989), pp. 69–72.
- J. J. Bollinger, W. M. Itano, D. J. Wineland, and D. J. Heinzen, Optimal frequency measurements with maximally correlated states, Phys. Rev. A 54, R4649(R) (1996).
- T. Monz, P. Schindler, J. T. Barreiro, M. Chwalla, D. Nigg, W. A. Coish, M. Harlander, W. Hänsel, M. Hennrich, and R. Blatt, 14-qubit entanglement: Creation and coherence, Phys. Rev. Lett. 106, 130506 (2011).
- A. Omran, H. Levine, A. Keesling, G. Semeghini, T. T. Wang, S. Ebadi, H. Bernien, A. S. Zibrov, H. Pichler, S. Choi, J. Cui, M. Rossignolo, P. Rembold, S. Montangero, T. Calarco, M. Endres, M. Greiner, V. Vuletić, and M. D. Lukin, Generation and manipulation of schrödinger cat states in Rydberg atom arrays, Science 365, 570 (2019).
- C. Song, K. Xu, H. Li, Y.-R. Zhang, X. Zhang, W. Liu, Q. Guo, Z. Wang, W. Ren, J. Hao, H. Feng, H. Fan, D. Zheng, D.-W. Wang, H. Wang, and S.-Y. Zhu, Generation of multicomponent atomic schrödinger cat states of up to 20 qubits, Science 365, 574 (2019).
- E. Knill and R. Laflamme, A theory of quantum error-correcting codes, Phys. Rev. Lett. 84, 2525 (2000).
- A. Bärtschi and S. Eidenbenz, Deterministic preparation of dicke states, in Fundamentals of Computation Theory, edited by L. A. Gasieniec, J. Jansson, and C. Levcopoulos (Springer International Publishing, Cham, 2019), pp. 126–139.
- X. Zou, K. Pahlke, and W. Mathis, Generation of arbitrary superpositions of the dicke states of excitons in optically driven quantum dots, Phys. Rev. A 68, 034306 (2003).
- S. C. Carrasco, M. H. Goerz, Z. Li, S. Colombo, V. Vuletić, and V. S. Malinovsky, Extreme spin squeezing via optimized one-axis twisting and rotations, Phys. Rev. Appl. 17, 064050 (2022).
- R. Kaubruegger, D. V. Vasilyev, M. Schulte, K. Hammerer, and P. Zoller, Quantum variational optimization of ramsey interferometry and atomic clocks, Phys. Rev. X 11, 041045 (2021).
- R. Kaubruegger, P. Silvi, C. Kokail, R. Van Bijnen, A. M. Rey, J. Ye, A. M. Kaufman, and P. Zoller, Variational spin-squeezing algorithms on programmable quantum sensors, Phys. Rev. Lett. 123, 260505 (2019).
- N. Gutman, A. Gorlach, O. Tziperman, R. Ruimy, and I. Kaminer, Universal control of symmetric states using spin squeezing, Phys. Rev. Lett. 132, 153601 (2024).
- C. D. Marciniak, T. Feldker, I. Pogorelov, R. Kaubruegger, D. V. Vasilyev, R. Van Bijnen, P. Schindler, P. Zoller, R. Blatt, and T. Monz, Optimal metrology with programmable quantum sensors, Nature (London) 603, 604 (2022).
- M. Kitagawa and M. Ueda, Squeezed spin states, Phys. Rev. A 47, 5138 (1993).
- See Supplemental Material at http://link.aps.org/supplemental/10.1103/PhysRevResearch.7.L022072 for further analysis of potential sources of error in trapped ions, and details on the implementation of the protocol as a hybrid quantum-classical algorithm, which also includes Refs. [69, 70, 71, 72, 73].
- F. Albertini and D. D'Alessandro, Controllability of symmetric spin networks, J. Math. Phys. 59, 052102 (2018).
- If there exists a control field such that , where is the transition element for a transition from an initial (final) state () for some finite protocol time , then the system is controllable.
- H. A. Rabitz, M. M. Hsieh, and C. M. Rosenthal, Quantum optimally controlled transition landscapes, Science 303, 1998 (2004).
- J. Nocedal and S. J. Wright, Numerical Optimization, Springer Series in Operations Research and Financial Engineering (Springer New York, 2006).
- J. Bezanson, A. Edelman, S. Karpinski, and V. B. Shah, Julia: A fresh approach to numerical computing, SIAM Review 59, 65 (2017).
- P. K. Mogensen and A. N. Riseth, Optim: A mathematical optimization package for Julia, J. Open Source Softw. 3, 615 (2018).
- An offset in the number of gates is needed to reach fidelities below the numerical termination threshold . For to the offset is either or , depending on the ceil function. For and the offset is , to give the numerical optimization more overhead to reach the termination threshold. Specifically, for we use gates.
- T. Keating, C. H. Baldwin, Y.-Y. Jau, J. Lee, G. W. Biedermann, and I. H. Deutsch, Arbitrary dicke-state control of symmetric Rydberg ensembles, Phys. Rev. Lett. 117, 213601 (2016).
- D. C. Liu and J. Nocedal, On the limited memory BFGS method for large scale optimization, Math. Program. 45, 503 (1989).
- I. Apellaniz, B. Lücke, J. Peise, C. Klempt, and G. Tóth, Detecting metrologically useful entanglement in the vicinity of dicke states, New J. Phys. 17, 083027 (2015).
- Y. Ouyang, N. Shettell, and D. Markham, Robust quantum metrology with explicit symmetric states, IEEE Trans. Inf. Theory 68, 1809 (2022).
- Note that the superposition of all states with only one qubit not excited can be prepared using the same sequence by applying a global spin flip at the end of the sequence, and that optimizing for rather than does not offer any potential for improvement as the initial state is an optimized CSS.
- P. W. Shor, Scheme for reducing decoherence in quantum computer memory, Phys. Rev. A 52, R2493(R) (1995).
- K. Mølmer and A. Sørensen, Multiparticle entanglement of hot trapped ions, Phys. Rev. Lett. 82, 1835 (1999).
- K. Kim, M.-S. Chang, R. Islam, S. Korenblit, L.-M. Duan, and C. Monroe, Entanglement and tunable spin-spin couplings between trapped ions using multiple transverse modes, Phys. Rev. Lett. 103, 120502 (2009).
- J. Britton, B. C. Sawyer, C.-C. J. W. A. C. Keith, J. Freericks, H. Uys, M. J. Biercuk, and J. J. Bollinger, Engineered two-dimensional ising interactions in a trapped-ion quantum simulator with hundreds of spins, Nature (London) 484, 489 (2012).
- J. Zhang, G. Pagano, P. W. Hess, A. Kyprianidis, P. Becker, H. Kaplan, A. V. Gorshkov, Z.-X. Gong, and C. Monroe, Observation of a many-body dynamical phase transition with a 53-qubit quantum simulator, Nature (London) 551, 601 (2017).
- G. Kirchmair, J. Benhelm, F. Zähringer, R. Gerritsma, C. F. Roos, and R. Blatt, Deterministic entanglement of ions in thermal states of motion, New J. Phys. 11, 023002 (2009).
- A. Sørensen and K. Mølmer, Entanglement and quantum computation with ions in thermal motion, Phys. Rev. A 62, 022311 (2000).
- W. Ge, B. C. Sawyer, J. W. Britton, K. Jacobs, J. J. Bollinger, and M. Foss-Feig, Trapped ion quantum information processing with squeezed phonons, Phys. Rev. Lett. 122, 030501 (2019).
- Y. Shapira, R. Shaniv, T. Manovitz, N. Akerman, L. Peleg, L. Gazit, R. Ozeri, and A. Stern, Theory of robust multiqubit nonadiabatic gates for trapped ions, Phys. Rev. A 101, 032330 (2020).
- J. D. Arias Espinoza, K. Groenland, M. Mazzanti, K. Schoutens, and R. Gerritsma, High-fidelity method for a single-step n-bit toffoli gate in trapped ions, Phys. Rev. A 103, 052437 (2021).
- L. Bond, L. Lenstra, R. Gerritsma, and A. Safavi-Naini, Effect of micromotion and local stress in quantum simulations with trapped ions in optical tweezers, Phys. Rev. A 106, 042612 (2022).
- J. R. McClean, J. Romero, R. Babbush, and A. Aspuru-Guzik, The theory of variational hybrid quantum-classical algorithms, New J. Phys. 18, 023023 (2016).
- A. Peruzzo, J. McClean, P. Shadbolt, M.-H. Yung, X.-Q. Zhou, P. J. Love, A. Aspuru-Guzik, and J. L. O'Brien, A variational eigenvalue solver on a photonic quantum processor, Nat. Commun. 5, 4213 (2014).
- G. Tóth, W. Wieczorek, D. Gross, R. Krischek, C. Schwemmer, and H. Weinfurter, Permutationally invariant quantum tomography, Phys. Rev. Lett. 105, 250403 (2010).
- G. Tóth, W. Wieczorek, R. Krischek, N. Kiesel, P. Michelberger, and H. Weinfurter, Practical methods for witnessing genuine multi-qubit entanglement in the vicinity of symmetric states, New J. Phys. 11, 083002 (2009).