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 Creative Commons Attribution 4.0 International license (CC BY 4.0)
When quoting this document, please refer to the following
DOI: 10.4230/LIPIcs.ITCS.2022.110
URN: urn:nbn:de:0030-drops-157063
URL: http://dagstuhl.sunsite.rwth-aachen.de/volltexte/2022/15706/
 
Peleg, Shir ; 
Volk, Ben Lee ; 
Shpilka, Amir 
Lower Bounds on Stabilizer Rank
Abstract
The stabilizer rank of a quantum state ψ is the minimal r such that |ψ⟩ = ∑_{j = 1}^r c_j |φ_j⟩ for c_j ∈ ℂ and stabilizer states φ_j. The running time of several classical simulation methods for quantum circuits is determined by the stabilizer rank of the n-th tensor power of single-qubit magic states.
We prove a lower bound of Ω(n) on the stabilizer rank of such states, improving a previous lower bound of Ω(√n) of Bravyi, Smith and Smolin [Bravyi et al., 2016]. Further, we prove that for a sufficiently small constant δ, the stabilizer rank of any state which is δ-close to those states is Ω(√n/log n). This is the first non-trivial lower bound for approximate stabilizer rank.
Our techniques rely on the representation of stabilizer states as quadratic functions over affine subspaces of ?₂ⁿ, and we use tools from analysis of boolean functions and complexity theory. The proof of the first result involves a careful analysis of directional derivatives of quadratic polynomials, whereas the proof of the second result uses Razborov-Smolensky low degree polynomial approximations and correlation bounds against the majority function.
BibTeX - Entry
@InProceedings{peleg_et_al:LIPIcs.ITCS.2022.110,
  author =	{Peleg, Shir and Volk, Ben Lee and Shpilka, Amir},
  title =	{{Lower Bounds on Stabilizer Rank}},
  booktitle =	{13th Innovations in Theoretical Computer Science Conference (ITCS 2022)},
  pages =	{110:1--110:4},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-217-4},
  ISSN =	{1868-8969},
  year =	{2022},
  volume =	{215},
  editor =	{Braverman, Mark},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/opus/volltexte/2022/15706},
  URN =		{urn:nbn:de:0030-drops-157063},
  doi =		{10.4230/LIPIcs.ITCS.2022.110},
  annote =	{Keywords: Quantum Computation, Lower Bounds, Stabilizer rank, Simulation of Quantum computers}
}
 
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Keywords: |  
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Quantum Computation, Lower Bounds, Stabilizer rank, Simulation of Quantum computers  | 
 
 
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Collection: |  
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13th Innovations in Theoretical Computer Science Conference (ITCS 2022) | 
 
 
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Issue Date: |  
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2022  | 
 
 
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Date of publication: |  
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25.01.2022  |