Cooperative quantum information erasure
Lorenzo Buffoni, Michele Campisi
Abstract
We demonstrate an information erasure protocol that resets <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>N</mml:mi></mml:math> qubits at once. The method displays exceptional performances in terms of energy cost (it operates nearly at Landauer energy cost <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>k</mml:mi><mml:mi>T</mml:mi><mml:mi>ln</mml:mi><mml:mo>&#x2061;</mml:mo><mml:mn>2</mml:mn></mml:math>), time duration (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mo>&#x223C;</mml:mo><mml:mi>&#x03BC;</mml:mi><mml:mi>s</mml:mi></mml:math>) and erasure success rate (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mo>&#x223C;</mml:mo><mml:mn>99</mml:mn><mml:mo>,</mml:mo><mml:mn>9</mml:mn><mml:mi mathvariant="normal">&#x0025;</mml:mi></mml:math>). The method departs from the standard algorithmic cooling paradigm by exploiting cooperative effects associated to the mechanism of spontaneous symmetry breaking which are amplified by quantum tunnelling phenomena. Such cooperative quantum erasure protocol is experimentally demonstrated on a commercial quantum annealer and could be readily applied in next generation hybrid gate-based/quantum-annealing quantum computers, for fast, effective, and energy efficient initialisation of quantum processing units.