TY - JOUR
T1 - Adiabatic Quantum Search in Open Systems
AU - Wild, Dominik S.
AU - Gopalakrishnan, Sarang
AU - Knap, Michael
AU - Yao, Norman Y.
AU - Lukin, Mikhail D.
N1 - Publisher Copyright:
© 2016 American Physical Society.
PY - 2016/10/6
Y1 - 2016/10/6
N2 - Adiabatic quantum algorithms represent a promising approach to universal quantum computation. In isolated systems, a key limitation to such algorithms is the presence of avoided level crossings, where gaps become extremely small. In open quantum systems, the fundamental robustness of adiabatic algorithms remains unresolved. Here, we study the dynamics near an avoided level crossing associated with the adiabatic quantum search algorithm, when the system is coupled to a generic environment. At zero temperature, we find that the algorithm remains scalable provided the noise spectral density of the environment decays sufficiently fast at low frequencies. By contrast, higher order scattering processes render the algorithm inefficient at any finite temperature regardless of the spectral density, implying that no quantum speedup can be achieved. Extensions and implications for other adiabatic quantum algorithms will be discussed.
AB - Adiabatic quantum algorithms represent a promising approach to universal quantum computation. In isolated systems, a key limitation to such algorithms is the presence of avoided level crossings, where gaps become extremely small. In open quantum systems, the fundamental robustness of adiabatic algorithms remains unresolved. Here, we study the dynamics near an avoided level crossing associated with the adiabatic quantum search algorithm, when the system is coupled to a generic environment. At zero temperature, we find that the algorithm remains scalable provided the noise spectral density of the environment decays sufficiently fast at low frequencies. By contrast, higher order scattering processes render the algorithm inefficient at any finite temperature regardless of the spectral density, implying that no quantum speedup can be achieved. Extensions and implications for other adiabatic quantum algorithms will be discussed.
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U2 - 10.1103/PhysRevLett.117.150501
DO - 10.1103/PhysRevLett.117.150501
M3 - Article
AN - SCOPUS:84991669306
SN - 0031-9007
VL - 117
JO - Physical review letters
JF - Physical review letters
IS - 15
M1 - 150501
ER -