_version_ 1866918356835106816
author Dasu, Shival
DeCross, Matthew
Guo, Andrew Y.
Lavasani, Ali
Behrends, Jan
Benhemou, Asmae
Chen, Yi-Hsiang
Mayer, Karl
Self, Chris N.
Simsek, Selwyn
Srivastava, Basudha
Allman, M. S.
Arkinstall, Jake
Bohnet, Justin G.
Burdick, Nathaniel Q.
Campora III, J. P.
Chernoguzov, Alex
Cooper, Samuel F.
Delaney, Robert D.
Dreiling, Joan M.
Estey, Brian
Figgatt, Caroline
Foltz, Cameron
Gaebler, John P.
Hall, Alex
Holliman, Craig A.
Husain, Ali A.
Isanaka, Akhil
Kennedy, Colin J.
Kodama, Yuga
Kotibhaskar, Nikhil
Lysne, Nathan K.
Madjarov, Ivaylo S.
Mills, Michael
Milne, Alistair R.
Neyenhuis, Brian
Park, Annie J.
Ransford, Anthony
Reed, Adam P.
Sanders, Steven J.
Baldwin, Charles H.
Hayes, David
Criger, Ben
Potter, Andrew C.
Amaro, David
author_facet Dasu, Shival
DeCross, Matthew
Guo, Andrew Y.
Lavasani, Ali
Behrends, Jan
Benhemou, Asmae
Chen, Yi-Hsiang
Mayer, Karl
Self, Chris N.
Simsek, Selwyn
Srivastava, Basudha
Allman, M. S.
Arkinstall, Jake
Bohnet, Justin G.
Burdick, Nathaniel Q.
Campora III, J. P.
Chernoguzov, Alex
Cooper, Samuel F.
Delaney, Robert D.
Dreiling, Joan M.
Estey, Brian
Figgatt, Caroline
Foltz, Cameron
Gaebler, John P.
Hall, Alex
Holliman, Craig A.
Husain, Ali A.
Isanaka, Akhil
Kennedy, Colin J.
Kodama, Yuga
Kotibhaskar, Nikhil
Lysne, Nathan K.
Madjarov, Ivaylo S.
Mills, Michael
Milne, Alistair R.
Neyenhuis, Brian
Park, Annie J.
Ransford, Anthony
Reed, Adam P.
Sanders, Steven J.
Baldwin, Charles H.
Hayes, David
Criger, Ben
Potter, Andrew C.
Amaro, David
contents High-rate quantum error correcting (QEC) codes encode many logical qubits in a given number of physical qubits, making them promising candidates for quantum computation. Implementing high-rate codes at a scale that both frustrates classical computing and improves performance by encoding requires both high fidelity gates and long-range qubit connectivity -- both of which are offered by trapped-ion quantum computers. Here, we demonstrate computations that outperform their unencoded counterparts in the high-rate $[[ k+2,\, k,\, 2 ]]$ iceberg quantum error detecting (QED) and $[[ (k_2 + 2)(k_1 + 2),\, k_2k_1,\, 4 ]]$ two-level concatenated iceberg QEC codes, using the 98-qubit Quantinuum Helios trapped-ion quantum processor. Utilizing new gadgets for encoded operations, we realize this "beyond break-even" performance with reasonable postselection rates across a range of fault-tolerant (FT) and partially-fault-tolerant (pFT) component and application benchmarks with between $48$ and $94$ logical qubits. These benchmarks include FT state preparation and measurement, QEC cycle benchmarking, logical gate benchmarking, GHZ state preparation, and a pFT quantum simulation of the three-dimensional $XY$ model of quantum magnetism. Additionally, we illustrate that postselection rates can be suppressed by increasing the code distance via concatenation. Our results represent state-of-the-art logical component and state fidelities and provide evidence that high-rate QED/QEC codes are viable on contemporary quantum computers for near-term beyond-classical-scale computation.
format Preprint
id arxiv_https___arxiv_org_abs_2602_22211
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Computing with many encoded logical qubits beyond break-even
Dasu, Shival
DeCross, Matthew
Guo, Andrew Y.
Lavasani, Ali
Behrends, Jan
Benhemou, Asmae
Chen, Yi-Hsiang
Mayer, Karl
Self, Chris N.
Simsek, Selwyn
Srivastava, Basudha
Allman, M. S.
Arkinstall, Jake
Bohnet, Justin G.
Burdick, Nathaniel Q.
Campora III, J. P.
Chernoguzov, Alex
Cooper, Samuel F.
Delaney, Robert D.
Dreiling, Joan M.
Estey, Brian
Figgatt, Caroline
Foltz, Cameron
Gaebler, John P.
Hall, Alex
Holliman, Craig A.
Husain, Ali A.
Isanaka, Akhil
Kennedy, Colin J.
Kodama, Yuga
Kotibhaskar, Nikhil
Lysne, Nathan K.
Madjarov, Ivaylo S.
Mills, Michael
Milne, Alistair R.
Neyenhuis, Brian
Park, Annie J.
Ransford, Anthony
Reed, Adam P.
Sanders, Steven J.
Baldwin, Charles H.
Hayes, David
Criger, Ben
Potter, Andrew C.
Amaro, David
Quantum Physics
High-rate quantum error correcting (QEC) codes encode many logical qubits in a given number of physical qubits, making them promising candidates for quantum computation. Implementing high-rate codes at a scale that both frustrates classical computing and improves performance by encoding requires both high fidelity gates and long-range qubit connectivity -- both of which are offered by trapped-ion quantum computers. Here, we demonstrate computations that outperform their unencoded counterparts in the high-rate $[[ k+2,\, k,\, 2 ]]$ iceberg quantum error detecting (QED) and $[[ (k_2 + 2)(k_1 + 2),\, k_2k_1,\, 4 ]]$ two-level concatenated iceberg QEC codes, using the 98-qubit Quantinuum Helios trapped-ion quantum processor. Utilizing new gadgets for encoded operations, we realize this "beyond break-even" performance with reasonable postselection rates across a range of fault-tolerant (FT) and partially-fault-tolerant (pFT) component and application benchmarks with between $48$ and $94$ logical qubits. These benchmarks include FT state preparation and measurement, QEC cycle benchmarking, logical gate benchmarking, GHZ state preparation, and a pFT quantum simulation of the three-dimensional $XY$ model of quantum magnetism. Additionally, we illustrate that postselection rates can be suppressed by increasing the code distance via concatenation. Our results represent state-of-the-art logical component and state fidelities and provide evidence that high-rate QED/QEC codes are viable on contemporary quantum computers for near-term beyond-classical-scale computation.
title Computing with many encoded logical qubits beyond break-even
topic Quantum Physics
url https://arxiv.org/abs/2602.22211