240 citations · 1.3k across the 22 of their papers we have counts for
22 papers
A pseudo-fermion method for the exact description of fermionic environments: from single-molecule electronics to Kondo resonance
Mauro Cirio, Neill Lambert, Pengfei Liang +5
We develop a discrete fermion approach for modelling the strong interaction of an arbitrary system interacting with continuum electronic reservoirs. The approach is based on a pseu…
Unveiling and veiling a Schrödinger cat state from the vacuum
Roberto Stassi, Mauro Cirio, Ken Funo +3
Deep in the ultrastrong light-matter coupling regime, it has been predicted that the ground state of a two-level atom interacting with a cavity mode takes the form of a "virtual" S…
Nonequilibrium heat transport and work with a single artificial atom coupled to a waveguide: emission without external driving
Yong Lu, Neill Lambert, Anton Frisk Kockum +5
We observe the continuous emission of photons into a waveguide from a superconducting qubit without the application of an external drive. To explain this observation, we build a tw…
General bound on the performance of counter-diabatic driving acting on dissipative spin systems
Ken Funo, Neill Lambert, Franco Nori
Counter-diabatic driving (CD) is a technique in quantum control theory designed to counteract nonadiabatic excitations and guide the system to follow its instantaneous energy eigen…
Superconducting-like heat current: Effective cancellation of current-dissipation trade off by quantum coherence
Hiroyasu Tajima, Ken Funo
Producing a large current typically requires large dissipation, as is the case in electric conduction, where Joule heating is proportional to the square of the current. Stochastic…
Shortcuts to Adiabatic Pumping in Classical Stochastic Systems
Ken Funo, Neill Lambert, Franco Nori +1
Adiabatic pumping is characterized by a geometric contribution to the pumped charge, which can be non-zero even in the absence of a bias. However, as the driving speed is increased…
Speeding-up a quantum refrigerator via counter-diabatic driving
Ken Funo, Neill Lambert, Bayan Karimi +3
We study the application of a counter-diabatic driving (CD) technique to enhance the thermodynamic efficiency and power of a quantum Otto refrigerator based on a superconducting qu…
Speed limit for open quantum systems
Ken Funo, Naoto Shiraishi, Keiji Saito
We study the quantum speed limit for open quantum systems described by the Lindblad master equation. The obtained inequality shows a trade-off relation between the operation time a…
Path integral approach to heat in quantum thermodynamics
Ken Funo, H. T. Quan
We study the heat statistics of a quantum Brownian motion described by the Caldeira-Leggett model. By using the path integral approach, we introduce a novel concept of the quantum…
Quantum Fluctuation Theorems
Ken Funo, Masahito Ueda, Takahiro Sagawa
Recent advances in experimental techniques allow one to measure and control systems at the level of single molecules and atoms. Here gaining information about fluctuating thermodyn…
Speed Limit for Classical Stochastic Processes
Naoto Shiraishi, Ken Funo, Keiji Saito
Speed limit for classical stochastic Markov processes with discrete states is studied. We find that a trade-off inequality exists between the speed of the state transformation and…
Path integral approach to quantum thermodynamics
Ken Funo, H. T. Quan
Work belongs to the most basic notions in thermodynamics but it is not well understood in quantum systems, especially in open quantum systems. By introducing a novel concept of wor…
Work fluctuation and total entropy production in nonequilibrium processes
Ken Funo, Tomohiro Shitara, Masahito Ueda
Work fluctuation and total entropy production play crucial roles in small thermodynamic systems subject to large thermal fluctuations. We investigate a trade-off relation between t…
Universal Work Fluctuations during Shortcuts To Adiabaticity by Counterdiabatic Driving
Ken Funo, Jing-Ning Zhang, Cyril Chatou +3
Counterdiabatic driving (CD) exploits auxiliary control fields to tailor the nonequilibrium dynamics of a quantum system, making possible the suppression of dissipated work in fini…
Work fluctuation-dissipation trade-off in heat engines
Ken Funo, Masahito Ueda
Reducing work fluctuation and dissipation in heat engines or, more generally, information heat engines that perform feedback control is vital to maximize their efficiency. The same…
Quantum nonequilibrium equalities with absolute irreversibility
Ken Funo, Yûto Murashita, Masahito Ueda
We derive quantum nonequilibrium equalities in absolutely irreversible processes. Here by absolute irreversibility we mean that in the backward process the density matrix does not…
Strong Local Passivity in Finite Quantum Systems
Michael Frey, Ken Funo, Masahiro Hotta
Passive states of quantum systems are states from which no system energy can be extracted by any cyclic (unitary) process. Gibbs states of all temperatures are passive. Strong loca…
General achievable bound of extractable work under feedback control
Yuto Ashida, Ken Funo, Yûto Murashita +1
A general achievable upper bound of extractable work under feedback control is given, where nonequilibrium equalities are generalized so as to be applicable to error-free measureme…
Nonequilibrium Equalities in Absolutely Irreversible Processes
Yûto Murashita, Ken Funo, Masahito Ueda
We generalize nonequilibrium integral equalities to situations involving absolutely irreversible processes for which the forward-path probability vanishes and the entropy productio…
Integral Quantum Fluctuation Theorems under Measurement and Feedback control
Ken Funo, Yu Watanabe, Masahito Ueda
We derive integral quantum fluctuation theorems and quantum Jarzynski equalities for a feedback-controlled system and a memory which registers outcomes of the measurement. The obta…
Black Hole Firewalls Require Huge Energy of Measurement
Masahiro Hotta, Jiro Matsumoto, Ken Funo
The unitary moving mirror model is one of the best quantum systems for checking the reasoning of the original firewall paradox of AMPS in quantum black holes. Though the late-time…
Thermodynamic Work Gain from Entanglement
Ken Funo, Yu Watanabe, Masahito Ueda
We show that entanglement can be utilized to extract thermodynamic work beyond classical correlation via feedback control based on measurement on part of a composite system. The ne…