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<button class="button is-small is-link">Go</button> </div> </div> </form> </div> </div> <ol class="breathe-horizontal" start="1"> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2409.13025">arXiv:2409.13025</a> <span> [<a href="https://arxiv.org/pdf/2409.13025">pdf</a>, <a href="https://arxiv.org/format/2409.13025">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> </div> <p class="title is-5 mathjax"> Hardware-efficient quantum error correction using concatenated bosonic qubits </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Putterman%2C+H">Harald Putterman</a>, <a href="/search/quant-ph?searchtype=author&query=Noh%2C+K">Kyungjoo Noh</a>, <a href="/search/quant-ph?searchtype=author&query=Hann%2C+C+T">Connor T. Hann</a>, <a href="/search/quant-ph?searchtype=author&query=MacCabe%2C+G+S">Gregory S. MacCabe</a>, <a href="/search/quant-ph?searchtype=author&query=Aghaeimeibodi%2C+S">Shahriar Aghaeimeibodi</a>, <a href="/search/quant-ph?searchtype=author&query=Patel%2C+R+N">Rishi N. Patel</a>, <a href="/search/quant-ph?searchtype=author&query=Lee%2C+M">Menyoung Lee</a>, <a href="/search/quant-ph?searchtype=author&query=Jones%2C+W+M">William M. Jones</a>, <a href="/search/quant-ph?searchtype=author&query=Moradinejad%2C+H">Hesam Moradinejad</a>, <a href="/search/quant-ph?searchtype=author&query=Rodriguez%2C+R">Roberto Rodriguez</a>, <a href="/search/quant-ph?searchtype=author&query=Mahuli%2C+N">Neha Mahuli</a>, <a href="/search/quant-ph?searchtype=author&query=Rose%2C+J">Jefferson Rose</a>, <a href="/search/quant-ph?searchtype=author&query=Owens%2C+J+C">John Clai Owens</a>, <a href="/search/quant-ph?searchtype=author&query=Levine%2C+H">Harry Levine</a>, <a href="/search/quant-ph?searchtype=author&query=Rosenfeld%2C+E">Emma Rosenfeld</a>, <a href="/search/quant-ph?searchtype=author&query=Reinhold%2C+P">Philip Reinhold</a>, <a href="/search/quant-ph?searchtype=author&query=Moncelsi%2C+L">Lorenzo Moncelsi</a>, <a href="/search/quant-ph?searchtype=author&query=Alcid%2C+J+A">Joshua Ari Alcid</a>, <a href="/search/quant-ph?searchtype=author&query=Alidoust%2C+N">Nasser Alidoust</a>, <a href="/search/quant-ph?searchtype=author&query=Arrangoiz-Arriola%2C+P">Patricio Arrangoiz-Arriola</a>, <a href="/search/quant-ph?searchtype=author&query=Barnett%2C+J">James Barnett</a>, <a href="/search/quant-ph?searchtype=author&query=Bienias%2C+P">Przemyslaw Bienias</a>, <a href="/search/quant-ph?searchtype=author&query=Carson%2C+H+A">Hugh A. Carson</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+C">Cliff Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+L">Li Chen</a> , et al. (96 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2409.13025v1-abstract-short" style="display: inline;"> In order to solve problems of practical importance, quantum computers will likely need to incorporate quantum error correction, where a logical qubit is redundantly encoded in many noisy physical qubits. The large physical-qubit overhead typically associated with error correction motivates the search for more hardware-efficient approaches. Here, using a microfabricated superconducting quantum circ… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.13025v1-abstract-full').style.display = 'inline'; document.getElementById('2409.13025v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2409.13025v1-abstract-full" style="display: none;"> In order to solve problems of practical importance, quantum computers will likely need to incorporate quantum error correction, where a logical qubit is redundantly encoded in many noisy physical qubits. The large physical-qubit overhead typically associated with error correction motivates the search for more hardware-efficient approaches. Here, using a microfabricated superconducting quantum circuit, we realize a logical qubit memory formed from the concatenation of encoded bosonic cat qubits with an outer repetition code of distance $d=5$. The bosonic cat qubits are passively protected against bit flips using a stabilizing circuit. Cat-qubit phase-flip errors are corrected by the repetition code which uses ancilla transmons for syndrome measurement. We realize a noise-biased CX gate which ensures bit-flip error suppression is maintained during error correction. We study the performance and scaling of the logical qubit memory, finding that the phase-flip correcting repetition code operates below threshold, with logical phase-flip error decreasing with code distance from $d=3$ to $d=5$. Concurrently, the logical bit-flip error is suppressed with increasing cat-qubit mean photon number. The minimum measured logical error per cycle is on average $1.75(2)\%$ for the distance-3 code sections, and $1.65(3)\%$ for the longer distance-5 code, demonstrating the effectiveness of bit-flip error suppression throughout the error correction cycle. These results, where the intrinsic error suppression of the bosonic encodings allows us to use a hardware-efficient outer error correcting code, indicate that concatenated bosonic codes are a compelling paradigm for reaching fault-tolerant quantum computation. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.13025v1-abstract-full').style.display = 'none'; document.getElementById('2409.13025v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 September, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Comments on the manuscript welcome!</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2307.08737">arXiv:2307.08737</a> <span> [<a href="https://arxiv.org/pdf/2307.08737">pdf</a>, <a href="https://arxiv.org/format/2307.08737">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevX.14.011051">10.1103/PhysRevX.14.011051 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Demonstrating a long-coherence dual-rail erasure qubit using tunable transmons </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Levine%2C+H">Harry Levine</a>, <a href="/search/quant-ph?searchtype=author&query=Haim%2C+A">Arbel Haim</a>, <a href="/search/quant-ph?searchtype=author&query=Hung%2C+J+S+C">Jimmy S. C. Hung</a>, <a href="/search/quant-ph?searchtype=author&query=Alidoust%2C+N">Nasser Alidoust</a>, <a href="/search/quant-ph?searchtype=author&query=Kalaee%2C+M">Mahmoud Kalaee</a>, <a href="/search/quant-ph?searchtype=author&query=DeLorenzo%2C+L">Laura DeLorenzo</a>, <a href="/search/quant-ph?searchtype=author&query=Wollack%2C+E+A">E. Alex Wollack</a>, <a href="/search/quant-ph?searchtype=author&query=Arrangoiz-Arriola%2C+P">Patricio Arrangoiz-Arriola</a>, <a href="/search/quant-ph?searchtype=author&query=Khalajhedayati%2C+A">Amirhossein Khalajhedayati</a>, <a href="/search/quant-ph?searchtype=author&query=Sanil%2C+R">Rohan Sanil</a>, <a href="/search/quant-ph?searchtype=author&query=Moradinejad%2C+H">Hesam Moradinejad</a>, <a href="/search/quant-ph?searchtype=author&query=Vaknin%2C+Y">Yotam Vaknin</a>, <a href="/search/quant-ph?searchtype=author&query=Kubica%2C+A">Aleksander Kubica</a>, <a href="/search/quant-ph?searchtype=author&query=Hover%2C+D">David Hover</a>, <a href="/search/quant-ph?searchtype=author&query=Aghaeimeibodi%2C+S">Shahriar Aghaeimeibodi</a>, <a href="/search/quant-ph?searchtype=author&query=Alcid%2C+J+A">Joshua Ari Alcid</a>, <a href="/search/quant-ph?searchtype=author&query=Baek%2C+C">Christopher Baek</a>, <a href="/search/quant-ph?searchtype=author&query=Barnett%2C+J">James Barnett</a>, <a href="/search/quant-ph?searchtype=author&query=Bawdekar%2C+K">Kaustubh Bawdekar</a>, <a href="/search/quant-ph?searchtype=author&query=Bienias%2C+P">Przemyslaw Bienias</a>, <a href="/search/quant-ph?searchtype=author&query=Carson%2C+H">Hugh Carson</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+C">Cliff Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+L">Li Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Chinkezian%2C+H">Harut Chinkezian</a>, <a href="/search/quant-ph?searchtype=author&query=Chisholm%2C+E+M">Eric M. Chisholm</a> , et al. (88 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2307.08737v3-abstract-short" style="display: inline;"> Quantum error correction with erasure qubits promises significant advantages over standard error correction due to favorable thresholds for erasure errors. To realize this advantage in practice requires a qubit for which nearly all errors are such erasure errors, and the ability to check for erasure errors without dephasing the qubit. We demonstrate that a "dual-rail qubit" consisting of a pair of… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.08737v3-abstract-full').style.display = 'inline'; document.getElementById('2307.08737v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2307.08737v3-abstract-full" style="display: none;"> Quantum error correction with erasure qubits promises significant advantages over standard error correction due to favorable thresholds for erasure errors. To realize this advantage in practice requires a qubit for which nearly all errors are such erasure errors, and the ability to check for erasure errors without dephasing the qubit. We demonstrate that a "dual-rail qubit" consisting of a pair of resonantly coupled transmons can form a highly coherent erasure qubit, where transmon $T_1$ errors are converted into erasure errors and residual dephasing is strongly suppressed, leading to millisecond-scale coherence within the qubit subspace. We show that single-qubit gates are limited primarily by erasure errors, with erasure probability $p_\text{erasure} = 2.19(2)\times 10^{-3}$ per gate while the residual errors are $\sim 40$ times lower. We further demonstrate mid-circuit detection of erasure errors while introducing $< 0.1\%$ dephasing error per check. Finally, we show that the suppression of transmon noise allows this dual-rail qubit to preserve high coherence over a broad tunable operating range, offering an improved capacity to avoid frequency collisions. This work establishes transmon-based dual-rail qubits as an attractive building block for hardware-efficient quantum error correction. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.08737v3-abstract-full').style.display = 'none'; document.getElementById('2307.08737v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 March, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 17 July, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">9+13 pages, 16 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Physical Review X 14, 011051 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2306.04044">arXiv:2306.04044</a> <span> [<a href="https://arxiv.org/pdf/2306.04044">pdf</a>, <a href="https://arxiv.org/format/2306.04044">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Mathematical Physics">math-ph</span> </div> </div> <p class="title is-5 mathjax"> Locality and Exceptional Points in Pseudo-Hermitian Physics </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Barnett%2C+J+L">Jacob L. Barnett</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2306.04044v1-abstract-short" style="display: inline;"> Pseudo-Hermitian operators generalize the concept of Hermiticity. This class of operators includes the quasi-Hermitian operators, which reformulate quantum theory while retaining real-valued measurement outcomes and unitary time evolution. This thesis is devoted to the study of locality in quasi-Hermitian theory, the symmetries and conserved quantities associated with non-Hermitian operators, and… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.04044v1-abstract-full').style.display = 'inline'; document.getElementById('2306.04044v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2306.04044v1-abstract-full" style="display: none;"> Pseudo-Hermitian operators generalize the concept of Hermiticity. This class of operators includes the quasi-Hermitian operators, which reformulate quantum theory while retaining real-valued measurement outcomes and unitary time evolution. This thesis is devoted to the study of locality in quasi-Hermitian theory, the symmetries and conserved quantities associated with non-Hermitian operators, and the perturbative features of pseudo-Hermitian matrices. In addition to the presented original research, scholars will appreciate the lengthy introduction to non-Hermitian physics. Local quasi-Hermitian observable algebras are examined. Expectation values of local quasi-Hermitian observables equal expectation values of local Hermitian observables. Thus, quasi-Hermitian theories do not increase the values of nonlocal games set by Hermitian theories. Furthermore, Bell's inequality violations in quasi-Hermitian theories never exceed the Tsirelson bound of Hermitian quantum theory. Exceptional points, which are branch points in the spectrum, are a perturbative feature unique to non-Hermitian operators. Cusp singularities of algebraic curves are related to higher-order exceptional points. To exemplify novelties of non-Hermiticity, one-dimensional lattice models with a pair of non-Hermitian defect potentials with balanced loss and gain, $螖\pm i 纬$, are explored. When the defects are nearest neighbour, the entire spectrum becomes complex when $纬$ is tuned past a second-order exceptional point. When the defects are at the edges of the chain and the hopping amplitudes are 2-periodic, as in the Su-Schrieffer-Heeger chain, the $\mathcal{PT}$-phase transition is dictated by the topological phase. Chiral symmetry and representation theory are used to derive large classes of pseudo-Hermitian operators with closed-form intertwining operators. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.04044v1-abstract-full').style.display = 'none'; document.getElementById('2306.04044v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 6 June, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">257 pages, 23 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2302.13204">arXiv:2302.13204</a> <span> [<a href="https://arxiv.org/pdf/2302.13204">pdf</a>, <a href="https://arxiv.org/format/2302.13204">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> </div> <p class="title is-5 mathjax"> Effects of detuning on $\mathcal{PT}$-symmetric, tridiagonal, tight-binding models </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Barnett%2C+J+L">Jacob L. Barnett</a>, <a href="/search/quant-ph?searchtype=author&query=Joglekar%2C+Y+N">Yogesh N. Joglekar</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2302.13204v1-abstract-short" style="display: inline;"> Non-Hermitian, tight-binding $\mathcal{PT}$-symmetric models are extensively studied in the literature. Here, we investigate two forms of non-Hermitian Hamiltonians to study the $\mathcal{PT}$-symmetry breaking thresholds and features of corresponding surfaces of exceptional points (EPs). They include one-dimensional chains with uniform or 2-periodic tunnelling amplitudes, one pair of balanced gai… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.13204v1-abstract-full').style.display = 'inline'; document.getElementById('2302.13204v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2302.13204v1-abstract-full" style="display: none;"> Non-Hermitian, tight-binding $\mathcal{PT}$-symmetric models are extensively studied in the literature. Here, we investigate two forms of non-Hermitian Hamiltonians to study the $\mathcal{PT}$-symmetry breaking thresholds and features of corresponding surfaces of exceptional points (EPs). They include one-dimensional chains with uniform or 2-periodic tunnelling amplitudes, one pair of balanced gain and loss potentials $螖\pm谋纬$ at parity-symmetric sites, and periodic or open boundary conditions. By introducing a Hermitian detuning potential, we obtain the dependence of the $\mathcal{PT}$-threshold, and therefore the exceptional-point curves, in the parameter space of detuning and gain-loss strength. By considering several such examples, we show that EP curves of a given order generically have cusp-points where the order of the EP increases by one. In several cases, we obtain explicit analytical expressions for positive-definite intertwining operators that can be used to construct a complex extension of quantum theory by re-defining the inner product. Taken together, our results provide a detailed understanding of detuned tight-binding models with a pair of gain-loss potentials. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.13204v1-abstract-full').style.display = 'none'; document.getElementById('2302.13204v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 February, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">27 pages, 5 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2002.04703">arXiv:2002.04703</a> <span> [<a href="https://arxiv.org/pdf/2002.04703">pdf</a>, <a href="https://arxiv.org/format/2002.04703">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1088/1751-8121/ac0732">10.1088/1751-8121/ac0732 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Nonlocality of Observables in Quasi-Hermitian Quantum Theory </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Barnett%2C+J">Jacob Barnett</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2002.04703v2-abstract-short" style="display: inline;"> Explicit construction of local observable algebras in quasi-Hermitian quantum theories is derived in both the tensor product model of locality and in models of free fermions. The latter construction is applied to several cases of a $\mathcal{PT}$-symmetric toy model of particle-conserving free fermions on a 1-dimensional lattice, with nearest neighbour interactions and open boundary conditions. De… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2002.04703v2-abstract-full').style.display = 'inline'; document.getElementById('2002.04703v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2002.04703v2-abstract-full" style="display: none;"> Explicit construction of local observable algebras in quasi-Hermitian quantum theories is derived in both the tensor product model of locality and in models of free fermions. The latter construction is applied to several cases of a $\mathcal{PT}$-symmetric toy model of particle-conserving free fermions on a 1-dimensional lattice, with nearest neighbour interactions and open boundary conditions. Despite the locality of the Hamiltonian, local observables do not exist in generic collections of sites in the lattice. The collections of sites which do contain nontrivial observables strongly depends on the complex potential. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2002.04703v2-abstract-full').style.display = 'none'; document.getElementById('2002.04703v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 22 May, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 11 February, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">25 pages, 1 figure</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1108.6083">arXiv:1108.6083</a> <span> [<a href="https://arxiv.org/pdf/1108.6083">pdf</a>, <a href="https://arxiv.org/format/1108.6083">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Statistical Mechanics">cond-mat.stat-mech</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevA.84.024103">10.1103/PhysRevA.84.024103 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Origin of maximal symmetry breaking in even PT-symmetric lattices </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Joglekar%2C+Y+N">Yogesh N. Joglekar</a>, <a href="/search/quant-ph?searchtype=author&query=Barnett%2C+J+L">Jacob L. Barnett</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1108.6083v1-abstract-short" style="display: inline;"> By investigating a parity and time-reversal (PT) symmetric, $N$-site lattice with impurities $\pm i纬$ and hopping amplitudes $t_0 (t_b)$ for regions outside (between) the impurity locations, we probe the origin of maximal PT-symmetry breaking that occurs when the impurities are nearest neighbors. Through a simple and exact derivation, we prove that the critical impurity strength is equal to the ho… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1108.6083v1-abstract-full').style.display = 'inline'; document.getElementById('1108.6083v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1108.6083v1-abstract-full" style="display: none;"> By investigating a parity and time-reversal (PT) symmetric, $N$-site lattice with impurities $\pm i纬$ and hopping amplitudes $t_0 (t_b)$ for regions outside (between) the impurity locations, we probe the origin of maximal PT-symmetry breaking that occurs when the impurities are nearest neighbors. Through a simple and exact derivation, we prove that the critical impurity strength is equal to the hopping amplitude between the impurities, $纬_c=t_b$, and the simultaneous emergence of $N$ complex eigenvalues is a robust feature of any PT-symmetric hopping profile. Our results show that the threshold strength $纬_c$ can be widely tuned by a small change in the global profile of the lattice, and thus have experimental implications. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1108.6083v1-abstract-full').style.display = 'none'; document.getElementById('1108.6083v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 5 August, 2011; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2011. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">3 pages, 1 figure</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. A 84, 024103 (2011) </p> </li> </ol> <div class="is-hidden-tablet">  <span class="help" style="display: inline-block;"><a href="https://github.com/arXiv/arxiv-search/releases">Search v0.5.6 released 2020-02-24</a>  </span> </div> </div> </main> <footer> <div class="columns is-desktop" role="navigation" aria-label="Secondary">  <div class="column"> <div class="columns"> <div class="column"> <ul class="nav-spaced"> <li><a href="https://info.arxiv.org/about">About</a></li> <li><a href="https://info.arxiv.org/help">Help</a></li> </ul> </div> <div class="column"> <ul class="nav-spaced"> <li> <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" class="icon filter-black" role="presentation"><title>contact arXiv</title><desc>Click here to contact arXiv</desc><path d="M502.3 190.8c3.9-3.1 9.7-.2 9.7 4.7V400c0 26.5-21.5 48-48 48H48c-26.5 0-48-21.5-48-48V195.6c0-5 5.7-7.8 9.7-4.7 22.4 17.4 52.1 39.5 154.1 113.6 21.1 15.4 56.7 47.8 92.2 47.6 35.7.3 72-32.8 92.3-47.6 102-74.1 131.6-96.3 154-113.7zM256 320c23.2.4 56.6-29.2 73.4-41.4 132.7-96.3 142.8-104.7 173.4-128.7 5.8-4.5 9.2-11.5 9.2-18.9v-19c0-26.5-21.5-48-48-48H48C21.5 64 0 85.5 0 112v19c0 7.4 3.4 14.3 9.2 18.9 30.6 23.9 40.7 32.4 173.4 128.7 16.8 12.2 50.2 41.8 73.4 41.4z"/></svg> <a href="https://info.arxiv.org/help/contact.html"> Contact</a> </li> <li> <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" class="icon filter-black" role="presentation"><title>subscribe to arXiv mailings</title><desc>Click here to subscribe</desc><path d="M476 3.2L12.5 270.6c-18.1 10.4-15.8 35.6 2.2 43.2L121 358.4l287.3-253.2c5.5-4.9 13.3 2.6 8.6 8.3L176 407v80.5c0 23.6 28.5 32.9 42.5 15.8L282 426l124.6 52.2c14.2 6 30.4-2.9 33-18.2l72-432C515 7.8 493.3-6.8 476 3.2z"/></svg> <a href="https://info.arxiv.org/help/subscribe"> Subscribe</a> </li> </ul> </div> </div> </div>   <div class="column"> <div class="columns"> <div class="column"> <ul class="nav-spaced"> <li><a href="https://info.arxiv.org/help/license/index.html">Copyright</a></li> <li><a href="https://info.arxiv.org/help/policies/privacy_policy.html">Privacy Policy</a></li> </ul> </div> <div class="column sorry-app-links"> <ul class="nav-spaced"> <li><a href="https://info.arxiv.org/help/web_accessibility.html">Web Accessibility Assistance</a></li> <li> <p class="help"> <a class="a11y-main-link" href="https://status.arxiv.org" target="_blank">arXiv Operational Status <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 256 512" class="icon filter-dark_grey" role="presentation"><path d="M224.3 273l-136 136c-9.4 9.4-24.6 9.4-33.9 0l-22.6-22.6c-9.4-9.4-9.4-24.6 0-33.9l96.4-96.4-96.4-96.4c-9.4-9.4-9.4-24.6 0-33.9L54.3 103c9.4-9.4 24.6-9.4 33.9 0l136 136c9.5 9.4 9.5 24.6.1 34z"/></svg></a><br> Get status notifications via <a class="is-link" href="https://subscribe.sorryapp.com/24846f03/email/new" target="_blank"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" class="icon filter-black" role="presentation"><path d="M502.3 190.8c3.9-3.1 9.7-.2 9.7 4.7V400c0 26.5-21.5 48-48 48H48c-26.5 0-48-21.5-48-48V195.6c0-5 5.7-7.8 9.7-4.7 22.4 17.4 52.1 39.5 154.1 113.6 21.1 15.4 56.7 47.8 92.2 47.6 35.7.3 72-32.8 92.3-47.6 102-74.1 131.6-96.3 154-113.7zM256 320c23.2.4 56.6-29.2 73.4-41.4 132.7-96.3 142.8-104.7 173.4-128.7 5.8-4.5 9.2-11.5 9.2-18.9v-19c0-26.5-21.5-48-48-48H48C21.5 64 0 85.5 0 112v19c0 7.4 3.4 14.3 9.2 18.9 30.6 23.9 40.7 32.4 173.4 128.7 16.8 12.2 50.2 41.8 73.4 41.4z"/></svg>email</a> or <a class="is-link" href="https://subscribe.sorryapp.com/24846f03/slack/new" target="_blank"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 448 512" class="icon filter-black" role="presentation"><path d="M94.12 315.1c0 25.9-21.16 47.06-47.06 47.06S0 341 0 315.1c0-25.9 21.16-47.06 47.06-47.06h47.06v47.06zm23.72 0c0-25.9 21.16-47.06 47.06-47.06s47.06 21.16 47.06 47.06v117.84c0 25.9-21.16 47.06-47.06 47.06s-47.06-21.16-47.06-47.06V315.1zm47.06-188.98c-25.9 0-47.06-21.16-47.06-47.06S139 32 164.9 32s47.06 21.16 47.06 47.06v47.06H164.9zm0 23.72c25.9 0 47.06 21.16 47.06 47.06s-21.16 47.06-47.06 47.06H47.06C21.16 243.96 0 222.8 0 196.9s21.16-47.06 47.06-47.06H164.9zm188.98 47.06c0-25.9 21.16-47.06 47.06-47.06 25.9 0 47.06 21.16 47.06 47.06s-21.16 47.06-47.06 47.06h-47.06V196.9zm-23.72 0c0 25.9-21.16 47.06-47.06 47.06-25.9 0-47.06-21.16-47.06-47.06V79.06c0-25.9 21.16-47.06 47.06-47.06 25.9 0 47.06 21.16 47.06 47.06V196.9zM283.1 385.88c25.9 0 47.06 21.16 47.06 47.06 0 25.9-21.16 47.06-47.06 47.06-25.9 0-47.06-21.16-47.06-47.06v-47.06h47.06zm0-23.72c-25.9 0-47.06-21.16-47.06-47.06 0-25.9 21.16-47.06 47.06-47.06h117.84c25.9 0 47.06 21.16 47.06 47.06 0 25.9-21.16 47.06-47.06 47.06H283.1z"/></svg>slack</a> </p> </li> </ul> </div> </div> </div>  </div> </footer> <script src="https://static.arxiv.org/static/base/1.0.0a5/js/member_acknowledgement.js"></script> </body> </html>

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