March 2026 - ITP-quantumseminare

Monday's QIT seminar
by Ladina Hausmann 27 Mar '26

27 Mar '26

Hi all, Next week, Pablo Restrepo will talk about “Can Linear Interactions Support Quantum Advantage?”. See below for the abstract. The talk will take place on Monday at 15:00 in HIT K52. Best, Ladina %%%%%%%%% Title: Can Linear Interactions Support Quantum Advantage? Abstract: In this talk, I will discuss whether a previously established quantum advantage in autonomous quantum control persists when the interaction is restricted from a nonlinear to a linear form. In a quantum clock control model with nonlinear coupling, squeezed states were shown to enhance the scaling of gate frequency with energy. Here, I reproduce this result numerically and compare it with a waveguide-based model, in which a travelling bosonic field couples linearly to a qubit. The analysis shows that, for linear interactions, the advantage of squeezed states disappears: the qubit dynamics are determined by the first moment of the field, while fluctuation energy does not contribute to the effective drive. This suggests that quantum resources are only operationally useful when the interaction can convert them into an effective qubit drive.

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Next weeks QIT seminar
by Ladina Hausmann 19 Mar '26

19 Mar '26

Hi all, Next week, our visitor Yelena Guryanova will talk about “Cloning Quantum Channels”. See below for the abstract. The talk will take place on Monday at 15:00 in HIT K52. Best, Ladina %%%%%%%%%% Title: Cloning Quantum Channels Abstract: For states, the no-cloning theorem is one of the first encounters in quantum information: an arbitrary unknown pure state cannot be perfectly copied onto a waiting register. It’s simple then to infer that cloning N states onto M register won’t work either, but relaxing the problem to allow for imperfect copying allows one to investigate the rate and quality of N-to-M cloning. But what if we go further? Can we imagine cloning the cloner, in other words, cloning the device itself? Our first result is to prove that cloning quantum states turns out to be a special case of this more general problem. We derive the strong converse on traditional state cloning and provide a novel bound on the linear replication rate. On this foundation, we build a unified framework that can address the most general cloning tasks using the language of higher-order quantum operations—we seek the meta-machines that allow us to clone the cloners. Results from 2015 already established that unitary devices can be super-replicated (these achieve a quadratic cloning rate with vanishing error) and we build on this and extend the devices to arbitrary quantum channels. We establish the necessary conditions for the super-replication of any family of channels and prove that super-replication is not possible for classical noise channels nor the amplitude-damping channel. Finally, we present numerical methods to search for optimal cloning processes and establish a connection between channel cloning and Bayesian channel estimation.

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No seminar next week
by Ladina Hausmann 13 Mar '26

13 Mar '26

Hi all, There is no seminar planned for next week. Best, Ladina

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Fwd: ITS Fellows' Seminar with Anne-Catherine de la Hamette
by Ladina Hausmann 09 Mar '26

09 Mar '26

Hi all, This talk by Anne-Catherine de la Hamette, that was also annouced in the seminar today, may be of interest to many of you. Best, Ladina > Begin forwarded message: > > From: Administration ETH-ITS <administration(a)eth-its.ethz.ch> > Subject: ITS Fellows' Seminar with Anne-Catherine de la Hamette > Date: 5 March 2026 at 13:28:46 GMT+1 > > Dear all, > > We are pleased to invite you to our next ITS Fellows' Seminar with Junior Fellow Anne-Catherine de la Hamette > > Title: Relational Perspectives in Quantum Gravity: Quantum Reference Frames > > When: Tuesday, March 10, 2026, 4:00 - 5:00 p.m. (continuous apero throughout the event) > > Where: ITS Seminar Room, Scheuchzerstrasse 70, Zurich > > For more details on the talk: Relational Perspectives in Quantum Gravity: Quantum Reference Frames <http://Relational Perspectives in Quantum Gravity: Quantum Reference Frames> > > We look forward to your participation and are happy to assist with any questions. > > Best, > Angela > > > > > Angela Munson > Coordinator / General Manager > ETH Zürich > Institute for Theoretical Studies > SEW D 25 > Scheuchzerstrasse 70 > CH–8092 Zürich > > http://www.eth-its.ethz.ch <http://www.eth-its.ethz.ch/> > <http://www.eth-its.ethz.ch/> > Institute for Theoretical Studies <http://www.eth-its.ethz.ch/> > The Swiss Federal Institute of Technology Zurich is a science and engineering university with an outstanding research record, located in the largest city in Switzerland, in the middle of Europe. > www.eth-its.ethz.ch <http://www.eth-its.ethz.ch/> > Phone: +41 44 632 35 07

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Monday's QIT seminar at 15:00 in HIT K51
by Ladina Hausmann 05 Mar '26

05 Mar '26

Hi all, Next Monday, Leonardo Finocchiaro will talk about “Generalized Quantum Stein’s Lemma and blurring map”. See below for the abstract. The talk will take place on Monday at 15:00 in HIT K51. Best, Ladina %%%%%%%%%% Title : Generalized Quantum Stein’s Lemma and blurring map Abstract : A common quantum hypothesis testing task is to decide whether a given state is entangled or not. Given more copies, it is possible to exponentially reduce the chance of making an error. The generalized Stein's lemma connects this rate of decay to the intrinsic relative entropy of entanglement of this state. It extends the result from the i.i.d. case, which itself relies on the original classical result from Chernoff and Stein. Recently this theorem was proven independently by Lami and Hayashi, and the former developed two new techniques, namely the blurring map and the bosonic lifting procedure. The goal of this presentation is to introduce the setup and build intuition around these tools. After reviewing the proof, we also consider some possible extensions of the result with the aim to find "one-shot" bounds, effectively bounding the rate of convergence.

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