/r/QuantumComputing

Photograph via snooOG

Academic discussion of all things quantum computing from hardware through algorithms. Not the place for business speculation, memes, or philosophy.

All about Quantum Computing


Guidelines

  • 0. Civility & Respect are expected. Please report any uncivil conduct.
  • 1. No accounts less than 2 days old allowed to post
    • Not enough karma or new account - this is to protect from spam. Ignoring this rule will get you temporarily or permanently banned by the AutoMod.
  • 2. Career/education questions only allowed in weekly megathread
    • Questions that are about career/education advice and not quantum computing itself are only allowed in the weekly megathread. Please leave a comment there instead of making a full post.
  • 3. Posts must be high quality
    • Posts cannot just be a link or vague question, please write something original and high quality for people to read and discuss.
  • 4. Posts must be on-topic
    • All posts must be quantum computing related. No posts about market speculation, quantum hype articles, how you should find a career, memes, etc.
  • 5. No incoherent/crank posts
    • This includes quantum mysticism, discussions about consciousness, claiming you solved P=NP, clearly not knowing the basics that you are posting about, etc.
  • 6. No AI-generated content
    • This subreddit is for academic discussion, posts that are primarily or entirely the output of an LLM without significant human discussion are not allowed. This includes comments; responses that are clearly generated by an LLM will be removed.
  • 7. No excessive advertising
    • In general, advertising self-made tools, organizations, and content is not allowed on this subreddit. However, personal projects, open source tooling, or upcoming events may be allowed at moderator discretion. If you're unsure, send us a message via modmail.
  • 8. No investment speculation
    • This subreddit is for academic discussion of the scientific field of quantum computing. It is NOT the place to discuss market trends, corporate performance, or investment speculation. See r/investing or similar for investment advice.
  • 9. Discussions about blockchain or AI must directly relate to quantum computing
    • While quantum computing is interdisciplenary and intersects various facets of computer science, physics, and cybersecurity, this subreddit is only to be used for content directly relating to quantum computing. Posts that minimally connect to quantum computing such as "What does quantum computing mean for bitcoin?" will be removed unless there is sufficient substance relating to quantum computing in the post body.
  • 10. No memes or joke posts
    • This subreddit is for academic discussion. See r/QuantumMemes for jokes about quantum computing.

    Other subreddits you may enjoy:


    Interesting Links


    Quantum Jobs Board

    Know of any great job sites relating to Quantum Computing? Message the Mods and we will add it here if the community deems it worthy.

    /r/QuantumComputing

    55,142 Subscribers

    2

    Where should I go?

    I am a freshman in my first semester of college and I recently decided I wanted to do quantum computing, but I'm not sure what I should do as far as my major. I get a lot of scholarship money from being a music major, which I prioritize less than my degree in Electrical Engineering (I am a double major). I eventually want to go to grad school somewhere that has quantum computing, but I don't even know where to begin as far as projects and what courses would be helpful to take before I apply for grad school. The scholarship money is important for now, as well. Does anyone have any advice?

    1 Comment
    2024/11/10
    05:48 UTC

    8

    I found a hidden gem of a textbook (free)

    I thought I would share this textbook I found online: https://qubit.guide/

    At this point in my learning journey, I've collected a few textbooks to help with different concepts, but this one is by far the best of them all, at least from a beginner's perspective. It is not overly rigorous or formulaic, but at the same time, it does not sacrifice formality for loose, hand-wavey intuition. It strikes a perfect balance between math and understanding. I would definitely recommend it to anyone at the undergraduate level studying quantum information.

    For reference, I'm a computer science undergrad with no background in physics or pure math.

    0 Comments
    2024/11/09
    22:02 UTC

    43

    The world's first universal optical quantum computing platform is launched - University of Tokyo, Japan

    The optical quantum computer developed this time is a measurement-induced analog quantum computer that uses time-division multiplexing. Here, an analog quantum computer refers to a continuous quantity (analog) quantum computer based on quanta represented as continuous quantities rather than bits. Specifically, the amplitude value of the light wave becomes the carrier (carrier medium) of information. By combining this with time-division multiplexing and measurement-induced technology, a large-scale and efficient quantum computer will be realized.

    The optical quantum computer is a cloud-based quantum computer. RIKEN's actual optical quantum computer is connected to the cloud. Users design quantum circuits and send them to the cloud. The quantum circuits are converted into actual device parameters in the cloud and sent to the actual optical quantum computer. Users receive the execution results through the cloud.

    Link: https://www.riken.jp/pr/news/2024/20241108_2/index.html

    (Japanese, need to use Google Translate)

    0 Comments
    2024/11/09
    20:32 UTC

    0

    Quantum Funding Question

    Do you think the Trump administration will make quantum funding a priority? I was recently able to attend both the Chicago Quantum Summit and U Chicago’s opening of their school for climate and sustainability and the vibe at each was worried about Trumps dedication to emerging tech or needs like climate change.

    The states leading the way on quantum are mostly democratic and Pritzker and Trump are not going to see eye to eye on many things.

    How do you see this playing out especially for the hubs in Chicago and Colorado?

    8 Comments
    2024/11/09
    12:30 UTC

    1

    Exploring Hydrogen Diffusion and Heat Conduction Problems Using Quantum Computing

    Hi, quantum computing community!

    I’m a complete newbie in quantum computing, coming from a background in applied math and mechanical engineering. I am primarily focusing on solving a three-dimensional hydrogen diffusion problem using a finite-element method in classical computing, analyzing how the relative error depended on grid density and time intervals, and verifying results with known analytical solutions.

    Now, I’m curious about whether quantum computing could offer any advantages in tackling similar three-dimensional, time-dependent diffusion or heat conduction problems. I’ve come across a few articles discussing quantum approaches to these types of problems(HHL?), but I’d love to get the latest feedback and hear your thoughts on whether it’s worth digging into quantum computing for this application.

    Has anyone here worked on something similar, or have suggestions for where to start? Are there specific quantum algorithms or methods that you think might be promising for such diffusion or conduction problems? Thanks in advance for any insights!

    0 Comments
    2024/11/09
    00:56 UTC

    3

    Weekly Career, Education, Textbook, and Basic Questions Thread

    Weekly Thread dedicated to all your career, job, education, and basic questions related to our field. Whether you're exploring potential career paths, looking for job hunting tips, curious about educational opportunities, or have questions that you felt were too basic to ask elsewhere, this is the perfect place for you.

    • Careers: Discussions on career paths within the field, including insights into various roles, advice for career advancement, transitioning between different sectors or industries, and sharing personal career experiences. Tips on resume building, interview preparation, and how to effectively network can also be part of the conversation.
    • Education: Information and questions about educational programs related to the field, including undergraduate and graduate degrees, certificates, online courses, and workshops. Advice on selecting the right program, application tips, and sharing experiences from different educational institutions.
    • Textbook Recommendations: Requests and suggestions for textbooks and other learning resources covering specific topics within the field. This can include both foundational texts for beginners and advanced materials for those looking to deepen their expertise. Reviews or comparisons of textbooks can also be shared to help others make informed decisions.
    • Basic Questions: A safe space for asking foundational questions about concepts, theories, or practices within the field that you might be hesitant to ask elsewhere. This is an opportunity for beginners to learn and for seasoned professionals to share their knowledge in an accessible way.
    1 Comment
    2024/11/08
    14:01 UTC

    11

    Quantum computing and exhaustive search

    Currently a PhD student looking into discrete optimisation (technically in stats as my objective functions come from posterior distributions).

    My research is looking into the best way to explore high dimensional discrete spaces. The optimisations can be solved directly if we could enumerate all possible values. On a classical computer this is practically impossible for the size of discrete space I am working with.

    Can quantum computing be used for exhaustive search in much faster ways?

    10 Comments
    2024/11/07
    15:08 UTC

    4

    Quantum Token Obfuscation via Superposition

    arXiv: https://arxiv.org/abs/2411.01252
    Abstract:
    As quantum computing advances, traditional cryptographic security measures, including token obfuscation, are increasingly vulnerable to quantum attacks. This paper introduces a quantum-enhanced approach to token obfuscation leveraging quantum superposition and multi-basis verification to establish a robust defense against these threats. In our method, tokens are encoded in superposition states, making them simultaneously exist in multiple states until measured, thus enhancing obfuscation complexity. Multi-basis verification further secures these tokens by enforcing validation across multiple quantum bases, thwarting unauthorized access. Additionally, we incorporate a quantum decay protocol and a refresh mechanism to manage the token life-cycle securely. Our experimental results demonstrate significant improvements in token security and robustness, validating this approach as a promising solution for quantum-secure cryptographic applications. This work not only highlights the feasibility of quantum-based token obfuscation but also lays the foundation for future quantum-safe security architectures.

    2 Comments
    2024/11/07
    14:49 UTC

    16

    Confused about Shor's algorithm working too well?

    Hello, I am a student doing a bit of Quantum Computing and for my project we have to look at Shor's algorithm. For this I updated this old Qiskit implementation of Shor's algorithm: https://github.com/Qiskit/qiskit/blob/stable/0.17/qiskit/algorithms/factorizers/shor.py

    I updated it to work on the latest qiskit version and I've been testing it on some numbers such as 15, 21, 69, 93 (5% success rate), 341 (10% success rate). Maybe this is really bad success rates? How can i find info on this?

    And I'm trying to find info online about what kind of numbers are feasible to do on real quantum hardware. But I only find cases of 15, 21 and trivial stuff like that. How come I'm getting good results on bigger numbers?

    Very confused about this would love some help!

    10 Comments
    2024/11/05
    23:02 UTC

    0

    An interesting talk on the role of Quantum, in an era where software eats the world, from Vishal Shete, Managing Director, Terra Quantum

    0 Comments
    2024/11/05
    18:45 UTC

    27

    Please help me guys I have no idea how to derive IX, ZX

    https://arxiv.org/abs/1603.04821 It’s from pg.3. My professor asked me to derive IX and ZX with rabi drive amplitudes but I have no idea how to do it.

    5 Comments
    2024/11/05
    16:18 UTC

    7

    An interesting interview with IBM and why they think post-quantum cryptography is so important.

    A pretty interesting conversation for those who are quantum curious. Won't be much for the hardened, but if you're new to the tech, should be some nuggets on types of cryptography and how IBM view it. The harvest now, decrypt later part is particularly important. https://open.spotify.com/episode/1lBMIDZjgoJBkrR5YtaNDj?si=8e2359aa13d94c06

    1 Comment
    2024/11/04
    13:01 UTC

    3

    A thoughtful talk on why quantum computing will become more and more important for machine learning and generative AI, from a leader in the field Richard Murray, CEO, ORCA Computing

    5 Comments
    2024/11/04
    12:15 UTC

    12

    What to expect at QIP (or similar) conference?

    Hey r/quantumcomputing!

    I'm excited (and a little nervous) because it’s my first time presenting at a conference (QIP 2025) -- most likely poster, but talk submission pending. I’d love any advice on what to expect, both in terms of the conference experience and presenting my research.

    Some specific questions:

    • What’s the typical vibe at QIP?
    • How do you usually approach networking with other researchers?
    • Any tips on presenting a poster in a way that engages people? My research is very math heavy, so how do you usually approach making posters for that
    • Are there any events or sessions that are “must-attend” for first-timers?

    Thanks for any insights! I’m really looking forward to this experience and want to make the most of it.

    0 Comments
    2024/11/03
    20:34 UTC

    8

    Quantum Key Distribution

    Fair warning, this is a rather lay post!
    I just learn't and i mean just now. That it is possible to use photons to encrypt information QKD and because interacting with the photons would cause them to change their Quantum state it is one, possible to detect eavesdropping and two, impossible to copy the encryption keys.
    I know how mundane this must be but I am utterly perplexed. I tend to think I'm reasonably current in my comprehension of technology but this is other wordly to me. My understanding of encryption ends at RSA, i have no idea what a Quantum state is or how in God's green earth a QBit can be Neither 1 or 0. What I'm sure about is the rabbit hole I'm about to go into.

    Here is your newest member!!
    That said, I have just one question what else have I missed?

    5 Comments
    2024/11/03
    12:54 UTC

    5

    Create a qasm file from a bqskit circuit object

    Hello, I am not too familiar with bqskit, and was wondering how I can get a qasm file from a bqskit circuit. There doesn't seem to be a dump feature, and the only way that I've found is to convert the circuit into a qiskit circuit.

    I tried to import the converter using "from bqskit.qiskit import BQskitToQiskitConverter," however I ran into an error where I can't access bqskit.qiskit even though I've already ran pip install bqskit and pip install qiskit in my venv.

    Could someone help me with this? Thanks! Im ngl I'm only really familiar with Qiskit.

    2 Comments
    2024/11/03
    02:51 UTC

    75

    Quantum Machines and Nvidia use machine learning to get closer to an error-corrected quantum computer

    An article based on interviews with Quantum Machines and Nvidia about how they used reinforcement learning to optimize pulses, improving performance and fidelity

    https://techcrunch.com/2024/11/02/quantum-machines-and-nvidia-use-machine-learning-to-get-closer-to-an-error-corrected-quantum-computer/

    11 Comments
    2024/11/02
    19:36 UTC

    5

    Weekly Career, Education, Textbook, and Basic Questions Thread

    Weekly Thread dedicated to all your career, job, education, and basic questions related to our field. Whether you're exploring potential career paths, looking for job hunting tips, curious about educational opportunities, or have questions that you felt were too basic to ask elsewhere, this is the perfect place for you.

    • Careers: Discussions on career paths within the field, including insights into various roles, advice for career advancement, transitioning between different sectors or industries, and sharing personal career experiences. Tips on resume building, interview preparation, and how to effectively network can also be part of the conversation.
    • Education: Information and questions about educational programs related to the field, including undergraduate and graduate degrees, certificates, online courses, and workshops. Advice on selecting the right program, application tips, and sharing experiences from different educational institutions.
    • Textbook Recommendations: Requests and suggestions for textbooks and other learning resources covering specific topics within the field. This can include both foundational texts for beginners and advanced materials for those looking to deepen their expertise. Reviews or comparisons of textbooks can also be shared to help others make informed decisions.
    • Basic Questions: A safe space for asking foundational questions about concepts, theories, or practices within the field that you might be hesitant to ask elsewhere. This is an opportunity for beginners to learn and for seasoned professionals to share their knowledge in an accessible way.
    6 Comments
    2024/11/01
    13:02 UTC

    9

    Last day to take the Quantum Open Source Software Survey!

    It's the last day to take the Quantum Open Source Software Survey by Unitary Fund! If you work in Quantum and haven't completed the survey, would love to hear from you! It helps us evaluate who is working in the field, what they are working on, what software and platforms work best for their work, and more.

    Thank you!!

    https://www.surveymonkey.com/r/qosssurvey24

    0 Comments
    2024/10/31
    18:30 UTC

    3

    Random parameterization to chi matrix

    8 Comments
    2024/10/31
    14:59 UTC

    5

    Looking to Understand Control and Tuning Process in Quantum Dot Auto-Tuning for Quantum Computers using Physics Informed Neural Networks

    Hi all! I’m planning my master’s thesis around a project which focuses on using Physics informed Neural Networks to automate control of spin qubits in silicon quantum dot arrays.

    The goal is to develop a solution for tuning of charge across many quantum dots (QDs), a crucial step toward scalable quantum computing. I have some basic understanding on how QDs work, quantum confinement and encoding quantum information in the electron spin, but I want to dig deeper into a few specific points:

    1-Control Mechanism: How exactly are we controlling the quantum dots? I assume it’s by adjusting gate voltages around each QD, but what’s the full setup like and how are we measuring back the outcome?

    2-Tuning Goals: What exactly are we tuning the voltage for? Is it to achieve specific charge or spin states in the QDs, or to stabilize interactions between dots? Or to have a single electron in each QD or to have specific energy levels? I am kind of lost on what the end goal is and why are we doing it.

    3-Validation: Once we adjust these parameters, how do we determine that the outcome is "correct" or optimal? Are there specific signals or current-voltage patterns we look for?

    Any detailed insights into this process would be amazing. I’m especially interested in how AI models, like Physics-Informed Neural Networks, detect and validate the desired patterns in current-voltage data. Thanks in advance for any guidance or resources you can share!

    4 Comments
    2024/10/31
    10:45 UTC

    7

    Attack Vectors of Quantum Computers - Sorin Boloș and Adrian Coleșa @ Quantum Village, DEF CON 32

    0 Comments
    2024/10/31
    09:56 UTC

    5

    Computation/Probability Question

    I am trying to understand decryption and am coming up against a basic understanding issue.

    If an algorithm has variable outputs, how is it possible to determine the input exactly.

    The simple way I have been trying to ask is: a coin is flipped in a vacuum and lands heads. How can you compute the state prior to the flip?

    EDIT: The context is I am trying to understand how SHA hashing algorithms are possibly reversible - with both traditional and quantum computers. To me it seems that they are not - and could only be decrypted through brute force input trials.

    4 Comments
    2024/10/31
    01:39 UTC

    3

    Applied learning

    Hi all: I’m admittedly new to the subject matter and know much less than most of you, so wanted to ask the collective a question. What type of types of applications of quantum computing will impact financial inclusion or banking more generally? Are there risks beyond simply security? I can imagine how the blending of commerce & finance, Big Tech data troves, and quantum could be a powerful manipulator on consumer behaviors but perhaps I’m not understanding quantum’s use cases appropriately. Relatedly, will quantum leverage Gen AI, change it, or replace it as now LLMs would be necessary?

    15 Comments
    2024/10/30
    12:45 UTC

    1

    A thoughtful talk on how and why businesses can prepare for quantum advantage from a leader in the field: Jan Goetz, CEO, IQM

    2 Comments
    2024/10/30
    10:44 UTC

    24

    I am a researcher specialising in solving large scale integer programming problems in classical computers. Should I learn and explore quantum computing for my research ? Will it have any advantage over classical computers in solving large scale problems

    26 Comments
    2024/10/28
    03:26 UTC

    16

    Quantum algorithms and optimization REU accepting applications

    The QAO REU site at the University of Tennessee Knoxville is accepting applications for summer 2025 until February 1. Applicants must be U.S. citizens or permanent residents. All STEM majors welcome to apply, however a linear algebra experience or Python programming skills will be useful. Please email the principal investigator on the webpage for more information.

    0 Comments
    2024/10/25
    16:31 UTC

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